England and Wales Patents County Court

IN THE PATENTS COUNTY COURT

		Royal Courts of Justice The Rolls Building 7 Rolls Buildings London EC4A 1NL.
		16 January 2013

HIS HONOUR JUDGE BIRSS:

1. In this action Mastermailer seeks a declaration of non infringement of Everseal's patent, GB2340073. The patent is entitled: "Business Forms with Adhesive Closure". The date of filing is 31^st July 1998. Mastermailer contends that its business forms, which are known as "mailers", do not infringe.
2. Mr. Tom Alkin, instructed by Shakespeares, appears for Mastermailer, and Mr. Robert Deacon, instructed by Jennings IP, appears for Everseal.
3. In this trial the issue of infringement is being heard as a preliminary issue. Mastermailer will seek to put validity in issue at a later date, only if it is necessary. The reasons for this unusual course are first that Mastermailer's primary case is that its products do not infringe and there is no need to get into validity. In addition, Everseal does not accept that Mastermailer can challenge validity in any event, as a result of the effect of a settlement agreement entered into at an earlier stage between these two parties. The settlement point only arises if Mastermailer needs to put validity in issue. Hence, if the case can be disposed of in this way, there will be a significant saving in time, cost and effort.
4. In the course of these proceedings, Everseal has applied to amend the patent. It does not seek to rely on the unamended patent. Mastermailer does not oppose the amendment. The Comptroller has given written observations. The Comptroller takes no issue with the amendments to the claim but there was a point on the specification. That was resolved by removing the word "preferably" at page 2 of the specification, line 15. No one suggested that the amendments add matter, extend the scope of protection or now introduce ambiguity. I agree. I will allow the amendments so the patent will be dealt with in amended form.
5. The only issue is infringement of claim 1, as proposed to be amended. There is also a claim for unjustified threats. These are said to have been made by Everseal to Mastermailer's supplier. Everseal says that they are not actionable within the meaning of the 1977 Patents Act. Mastermailer does not advance a positive case that they are actionable in response to what Everseal say. The only real significance of the threats action is that it may have an impact on the scope of any declaration to be granted.

Witnesses.

6. Mastermailer called Mr Morris. He is the operations manager at Document Management Solutions Ltd, (DMS), which is a manufacturer of business forms. One of its clients is Mastermailer. It makes the products alleged to infringe. Mr. Morris has extensive experience of business forms, dating back to the 1970s. From 1998 to 2002 he ran Laser Image, a Bowater company, which dealt with business forms. In 2002 he joined Mastermailer and set up their manufacturing operation. This manufacturing operation was sold by Mastermailer in 2004. The manufacturing operation has passed through a number of hands since, but Mr. Morris has stayed with it. His experience included the choice and use of adhesives in business forms, but he accepted that he was not an adhesive specialist.
7. Everseal called Mr Palmer. In the 1970s Mr. Palmer obtained a BSc. in chemistry and an MSc. in organic chemistry at the University of Birmingham. In his career, he worked for Dunlop Adhesives, Tivoli Kay Adhesives, Evo and Bostick, among others. Since 2007 he has worked as a technical consultant to the adhesives and sealant industry.

The person skilled in the art

8. It is not in dispute that the person skilled in the art will be a team concerned with producing business forms. That team will include someone who is an adhesive specialist. They will, perhaps, have a BSc. in the relevant science.

Common general knowledge

9. Mr. Morris gave unchallenged evidence which dealt with the common general knowledge of a person skilled in the art in 1998. It was as follows:

"13. To the best of my knowledge, mailers first emerged in the 1970s/1980s with the spread of the computer and computer printer in offices. Early printers were sprocket fed with continuous lengths of fan-folded, perforated paper. Business forms manufacturers and other engineering type companies (i.e PFE/Neopost referred to above) developed machines that could take the output of these printers and then "burst" (separate) the forms to individual sheets. Many of these forms would ultimately be inserted individually into conventional envelopes for posting. Similarly, with the development of pressure seal and pressure sensitive adhesives, forms could be mailed without the use of an envelope. Some manufacturers sold these machines together with fan-folded business forms.

14. Early mailer technology changed with the spread of laser printers able to print on an individual A4 sheets. Business forms manufacturers responded with single sheet 'pressure seal' mailers made from laser printer paper. Pressure seal adhesive is dry and non-tacky to the touch but will seal strongly to itself (a 'contact' adhesive) if two opposing layers are placed under high pressure. The seal produced by a pressure seal adhesive at pressure is so strong that it is practically impossible to re-separate bonded layers of paper without damage to the paper. In the industry this is known as 'fibre tear'. This has always been a standard measure of good bond strength in sealable mailers.

15 The advantage of pressure seal mailers was that they could be run through laser printers like any other sheet of paper. The disadvantage was that they needed an expensive machine to generate the high pressures needed to seal them.

16. From memory, Paragon Business Forms Limited was the first company to start selling pressure-seal mailers in the UK in the late 1980s/early 1990s. When I moved to Laser Image Limited in 1988 ort 1989, Bowater was in the process of developing its own pressure-seal mailing system. One of our main tasks at Laser Image was to run trials of various paper and adhesive types, alone and in combination, as part of this development.

17. Following the rise of the pressure-seal mailer, in the 1990s 'pressure sensitive' mailers began to become popular as well. A pressure sensitive mailer incorporates a pressure sensitive adhesive strip covered by a protector (usually made of silicone paper). Pressure sensitive adhesive is what is known as "live" adhesive. It is tacky to the touch, does not generally set and will remain usable for a long period of time (assuming it is not contaminated). This type of mailer was capable of being passed through a printer in order to be filled in. In order to seal it, the protector is peeled off, the form is folded and then the adhesive can be pressed by hand directly against an opposing paper surface to seal the mailer. The same system is used in envelopes today. The seal produced by a 'live' pressure sensitive adhesive at low pressure is also strong enough to make it very difficult to re-separate the bonded layers without causing fibre tear.

18. The advantage of pressure sensitive mailers is that they could be sealed manually. The disadvantage was the need to remove the protective paper strip, which becomes time consuming if one has a batch of mailers to seal.

19. In 1998 I would estimate that pressure seal mailers [had] about 70% of the mailer market, pressure sensitive mailers about 20% (although this share was growing). The remainder was made up mostly of "re-moist" mailers and heat sealable mailers. Re-moist mailers incorporated wettable adhesive which would dry to an opposing paper layer to form a bond, i.e. basic envelope and postage stamp technology. The adhesive on heat sealable mailers looked very similar to re-moist mailers, but the adhesive was activated by the application of heat through a special machine. "

10. I accept Mr. Morris's evidence on this.
11. One thing not mentioned expressly by Mr Morris, but which is self-evident, is that the point of this inability that he has referred to, to re-separate the bonded layers of paper in a mailer, is because one of the key uses of these mailers is for sending secure and confidential information, such as using them as pay slips. The point of this is that while one cannot prevent a third party from opening the mailer before it reaches the addressee, on the other hand, if the mailer cannot be resealed without that tampering being evident, then that will discourage the tampering.
12. Something that was not common general knowledge was a particular expedient used today to make tampering evident. This is the use of so called "anti-tamper slits". Mr. Morris said the following.

"22. I have been asked specifically whether mailers incorporating 'anti-tamper slits' or 'tamper evident slits' were common general knowledge in July 1998. 'Anti-tamper slits' are slits cut into the adhesive bearing paper of a mailer in order to create a line of weakness. The purpose of such slits is to ensure that if anyone tries to re-open a sealed mailer the paper will tear. This prevents a mailer being re-opened and re-sealed without this being evident.

23. Mastermailer started using anti-tamper slits in or around 2007 to give their mailers added security. Before this I had not seen any other products on the market in the UK that did so. For this reason I do not think that anti-tamper slits formed part of the common general knowledge at or before the priority date of the Patent. As I have mentioned above, the vast majority of mailers on the market at this time was made up of pressure seal and pressure sensitive mailers. Anti-tamper slits were not used on such mailers because the adhesives used made it very difficult to re-open them without causing damage to the unmodified paper."

13. I accept these parts of Mr. Morris's evidence.

The patent

14. There was no controversy about the law of patent construction. The law, essentially, is as stated by the House of Lords Kirin Amgen [2004] UKHL 46.
15. The patent starts as follows:

"This invention relates to business forms with adhesive closures and to the manufacture thereof. Use is particularly envisaged in relation to sealable mailers; ie, forms or letters which have at least one printable region and which are to be folded after printing or other appropriate mode of completion and sealed in a folded condition by means of one or more adhesive regions provided on the form, so as to be suitable for sending by post or in some other manner in which it should remain sealed in the folded condition. The form may have e.g. a standard letter text with one or more printable fields for printing of selected data; (e.g. address, name, file, reference data) or a printed form layout or grid for completion with specific data by printer, typing or by hand."

16. Thus, the invention is about mailers which have adhesive regions on them so that they can be folded over and sealed in order to be posted.
17. The next section in the specification describes three known kinds of adhesive. First, a re-moist adhesive, which is the familiar lick and stick method of sticking old-fashioned envelopes and stamps. Second, a silicone-based contact adhesive. This needs a high-pressure machine for its operation. Third a high-tack pressure sensitive adhesive, which needs much less pressure to be sealed but has a release layer which needs to be removed before it can be used. These three kinds of adhesive correspond to the common general knowledge that Mr. Morris has identified in the passages that I have quoted above.
18. The proposal at the heart of the invention is explained at page 2, line 7, of the specification onwards. It is to use a non-tacky layer of a dry self-sealing contact adhesive. The point of this adhesive is that it does not need high pressures, such as the second type of adhesive above, nor does it need a release layer, such as the third type of adhesive referred to above. As a result, the mailers can be sealed by hand.
19. The specification states:

A form or mailer as proposed is in practice a dry seal form or mailer that can be sealed by hand without requiring the use of a sealing machine. Sealing machines are expensive, typically being engineered to exert pressures in the range of 20-60 MPa (3,000-8000 lb/in²) as required by the conventional dry-seal contact adhesives. Thus, the present proposals open the way, for example, to small-scale use of direct mail by organisations who, for one reason or another, cannot run a sealing machine. The proposal also opens the way to fold, seal and return response forms, which can easily be used by the ordinary recipient without the need to wet an adhesive strip – a common source of discontent. [p 2 ln18, to p3 ln5]

20. The patent refers to the adhesive as being one which "self seals irreversibly". This can be seen in two passages in the specification: at page 2, lines 7-16 and page 3, lines 6-10. They are as follows:

"What we now propose is a new and useful business form or mailer of the type described above, which uses as the or each adhesive region, a non-tacky layer of a dry self-sealing contact adhesive which self-seals irreversibly to an opposed adhesive layer of the same kind, when the form has been folded to its folded condition, under a sealing pressure applied on that region which is finger pressure or alternatively stated, a pressure of 500kPa or less or 300kPa or less, but preferably at leatst 10kPa." (Page 2, lines 7-16)

"The reference above to an irreversible self seal is to be interpreted as meaning that subsequent re-separation of the layers results in disruption of the adhesive structure, also in the base material." (Page 3 lines 6-10)

21. There was a debate before me about the meaning of this irreversible self seal. The debate relates to the claim and I will come back to that below. At this stage, however, it is worth noting that the patent does not spell out the reasons why irreversibility is desirable. As I have mentioned before, the point of it is plainly to allow the business forms to be secure by ensuring that any attempt to open the mailer is evident. It is clear that the references to the figures in kilopascals (kPa) and megapascals (MPa) are in the context that the purpose of the patent is to produce a product which can be sealed by hand. The figures are an attempt to provide a more specific definition than a mere reference to hand or finger pressure, since that could, obviously, vary relatively widely and would be a vague criterion to try and rely on to delimit the claimed invention.
22. It is not necessary to go further through the specification in any detail. An example is given. Figures 1 and 2 are views of the example mailer:

23. Its properties are described at page 8, line 5, to page 9, line 4, as follows:

A characteristic of the present one-piece mailer is the nature of the adhesive layer 50 on the adhesive border 3. The adhesive 50 is selected and applied as an essentially tack-free layer - which will therefore not stick to opposed paper services, eg. if the forms are stacked – which will self adhere on contact with another part of the adhesive region 3 under finger pressure only. The present example uses a nature rubber latex adhesive stabilised with ammonia. In our work we used L516/4 adhesive supplied by Sealock. When applied as a sufficiently thin layer, this adhesive is essentially tack free.

After printing or writing of the relevant fields, the one-piece mailer invoice is used by folding the sheet in half about the centre line 18 to superimpose the opposed C-lines of the adhesive region 3. These are then pressed together using finger pressure, which creates an irreversible adhesive bond on contact. The printer-driver strips 6 are then torn away by means of the outer perforation, line 62, and discarded so that the mailer can be sent out. It acts as its own envelope concealing the data on the invoice in the known manner. The recipient of the completed document can open it by tearing away the adhesive side strips 5 and end strips 4 by means of the inner-perforation lines 52.

24. It may be noted that this passage refers to finger pressure.

Claim 1

25. As amended, claim 1 is as follows:

A business form with an adhesive closure having one or more adhesive regions for holding the form in a folded condition, characterised by the use on the adhesive region of a non-tacky layer of a dry self-sealing contact adhesive, which in the folded condition self-seals irreversibly to an opposed adhesive region, also carrying a said contact adhesive, the adhesive being selected to self-seal irreversibly under a pressure of 500 kPa or less.

26. The issues on construction are the following three. First, what does the patent mean by "selected"? Second, what is the meaning of "irreversibly" or "self seals irreversibly"? It is clear in that context that the specification of the claim requires one to go back in the specification to the definition at page 3, line 6, but the argument is about what does the definition at page 3, line 6, mean. Third, is it legitimate when considering a business form to include the presence of what are called "anti-tamper strips"? I will deal with these issues in turn.

Selected

27. "Selected" carries the idea that the adhesive must have been chosen carefully. However, one must be careful to avoid subjectivity here. Mr Alkin submitted that the word meant that the behaviour of the product had to be consistent. It would not be enough if a single mailer, as it were, an outlier in a test, exhibited the relevant property. I agree that the word "selected" carries with it the concept of a consistent behaviour. It seems to me that that is the limit of this expression.

Irreversible

28. As I have said already, this is clearly a reference back to page 3, lines 6-10 of the specification. As amended, the specification makes it clear that one needs both disruption of the adhesive structure and also disruption "in the base material". If there was just disruption of the adhesive without disrupting the base material, that is not enough.
29. Even if the disruption to the adhesive meant that it could not really be said that the mailer could be "re-sealed" or stuck back together again, the skilled reader would not think that the patent was referring just to sticking the mailer back together again in that sense. After all, even if you rip the paper you can still stick the mailer back together again. It would just be very obvious what has happened. The disruption referred to does not necessarily prevent re-sticking altogether. The skilled reader would understand that the patent is talking about evidence of tampering. The re-seal is not irreversible if it does not take the mailer back essentially to its pre-opened state; or, in other words, the sort of reversible re-seal that the patent is trying to avoid is reversible in the sense that it makes the mailer look as good as new to a practical extent.
30. No details of any test are laid down for irreversibility, and in particular for any disruption of the base material, nor are any details set out in the patent as to what test should be carried out to test the numerical limit of the pressures. Nevertheless, the patent is a practical document and aimed at practical people.
31. The questions which arise in relation to irreversibility are these. First, is disruption in the base material limited to fibre tear? Mr Alkin said it was, because fibre tear was a standard test as part of the common general knowledge. Second, does disruption in the base material include any visually-apparent deformation of the base material? That, essentially, was one or part of Mr Deacon's submissions. Third, does it include any visible disruption like the lifting of ink from one surface to the other? That was a matter that arose in the evidence.
32. Mr Alkin urged that fibre tear was a well understood and practical test – I accept that – but I am not satisfied that it is fair to read fibre tear into this patent. The skilled reader would have fibre tear as part of his common general knowledge and would assume that the patentee knew of it as well. Thus, the reader is entitled to think that if the inventor had meant "fibre tear", he could easily have said so. In my judgment, the words "disruption in the base material" do not bear the gloss of "fibre tear". The words are, as I have said, "disruption in the base material". That will include deformations, which are substantial enough to make tampering genuinely evident. If the person skilled in the art can see that the whole thing is so wrinkled and deformed that it has obviously been stuck back together again, even if it is not torn, then the original seal was, plainly, irreversible. If fibre tear takes place, then the original seal will certainly have been irreversible, but I do not accept that it is limited to fibre tear. However, I do not think it includes ink transfer. That is going too far.
33. Furthermore, if Mr Deacon's submission were that any visually apparent deformation of any sort would be enough – I do not agree that the matter can be taken that far either. It is a practical test, and I doubt that the skilled person would, in fact, have any difficulty applying it. For example, one could simply look at the re-sealed mailer and see if it had clearly been opened before. If the disruption of the base material (and the adhesive) makes the tampering evident, then the seal was irreversible.

Are tamper-evident slits included?

34. Mr Alkin submitted that they were not to be included. He said that that was because the claim was concerned with a property of the adhesive, not a property of the base material. He also said that anti-tamper slits should not be taken into account because they were a different solution to the same problem that the patent seeks to solve. Mr Deacon did not agree. He submitted that anti-tamper slits should be taken into account.
35. It seems to me that the claim is to a mailer and not to an adhesive. Although the ability to self seal irreversibly is dependent on the properties of the adhesive, it is not only dependent on those properties. It is a property of the mailer as a whole. For example, fibre tear, which if it occurred would be within the ambit of irreversibility, will depend on the strength of the particular base material itself. Also obviously relevant to the properties of the adhesive in the mailer is the thickness of the actual adhesive layer. For example, the claim requires the adhesive to be low tack and, as the patent acknowledges, that property depends on the thickness of the adhesive layer (page 5, lines 18-25).
36. I reject the argument that the claim is talking about the intrinsic properties of the adhesive. It seems to me that the base material has to be taken as it is. If the base material includes anti-tamper strips, then they must be taken into account as well. Mr. Alkin argued that the fact that they were not common general knowledge in 1998 means that they should be ignored for the purposes of assessing whether the article falls within the claim. I do not accept that. The same logic would mean that a base material made of a special kind of paper, which was not known in 1998, which was particularly weak and easy to tear, would have to be ignored somehow. I do not agree with that.
37. Mr Alkin also argued that the claim should not be construed this way because, if it was, it would be Biogen insufficient. It would, he said, exceed the technical contribution disclosed since the technical contribution is the use of this sort of special adhesive in a mailer. I accept that a concern for insufficiency can, in some cases, be a factor to be taken into account in construction (see for example AHP v Novartis [2001] EWCA Civ 165 – the rapamycin case). However, I do not believe that this is a valid argument in this case. The invention is not just an adhesive. The invention is a mailer with various parts arranged in a particular way and with certain properties. I do not believe that any concern about possible insufficiency would lead the reader to conclude in favour of Mr Alkin's construction.

The Experiments.

38. Mastermailer's first tests were conducted on 12^th April 2012 by a company called Westmoreland. They used a load cell and applied a load. 110 tests were run at various different pressures using the load cell. Each test was of a small square of material about 4cm x 4cm cut from a mailer. The mailers used did not have tamper-evident slits.
39. The modes of failure were defined as follows:

Mode 1: "The sample is intact after peeling and can be resealed."

Mode 2: "The sample is intact after peeling but cannot be resealed."

Mode 3: "The sample tears during peeling and cannot be resealed."

40. A mode of failure for each sample was attributed on this basis. The experiments were done at room temperature and at a higher temperature, 35 degrees C. 78 of the tests were at room temperature and the remainder at 35 degrees C. Mastermailer submit that the effect of the experiments was that the seal on the mailers was reversible below 1 MPa pressure. It was only irreversible above 1 MPa pressure. There was no significant effect of temperature.
41. The results were summarised in figure A2 of the report of the experiments. Below 1.135 MPa the only mode of failure was mode 1, save in one example. In that example, the failure mode was mode 3. Mr Alkin says that that one example was an outlier and not evidence of consistent behaviour. I accept his submission on that.
42. Mastermailer arranged for Westmoreland to conduct witnessed repeats on 3^rd October 2012. In the witness repeats the same test was performed on a smaller number of samples, and the same essential result was obtained overall.
43. Mastermailer submits, supported by Mr Morris, that these results show that the mailer can be readily resealed when it was sealed originally at a pressure below 1 MPa. It is only irreversibly sealed at an original pressure above 1 MPa. The hallmark of irreversibility, they contend, is fibre tear. Mr Morris's view was that more pressure gives a better seal, and this explains why one sees irreversibility only at higher pressures. On Mastermailer's case, the experiment shows that the materials tested were outside the claim.
44. Everseal submits that the tests were not representative. The pieces tested were too small and they had no anti-tamper slits. Mr Palmer did not challenge the allocation of the samples to the particular modes. He said he could see disruption of the adhesive surface in all the test samples in the witnessed repeat. I accept his evidence, but that is not evidence, necessarily, of disruption to the base material.

Everseal's first experiment conducted by Mr Palmer on 22^nd October 2012

45. This experiment was conducted at Loughborough University's Department of Materials. It involved applying a weight of a given mass to a small area. Essentially it is like a crude version of the Westmoreland experiments. The relevant area was looked at and judged by eye, including using a magnifying glass, to see how much of the area failed in different modes. Mr Palmer's definitions of "failure modes" were as follows:

Mode 1: No adhesive film disruption.

Mode 2: Adhesive film disruption (adhesive film to adhesive film failure)

Mode 3: Adhesive removal from substrate

Mode 4: Paper tearing (substrate failure).

46. Again, the test was done at two different temperatures but there was no significant effect of temperature.
47. In this experiment, there was an attempt to characterise the amount of different failure modes in a given sample. Quite a lot of the focus of the experiment was on adhesive failure, but that was clearly because Mr Palmer had prepared the experiments on the basis of the unamended patent. The definition of "irreversibility" in the unamended patent will be satisfied by disruption of the adhesive without disruption of the base layer. He was not focused on disruption of the base layer in this experiment.
48. It is true that there is not much fibre tear in this experiment. Some samples had some. By my count, there were nine out of 45 tested in the room-temperature test, and only one at a pressure below 500 kilopascals. All the fibre tears were in tamper-evident slits. Mr Palmer's opinion was that he was still concerned about the small size of the samples. He thought that more work needed to be done and he needed to look at dynamic loads. He said that the adhesive used in the mailers bonds to itself and not to other materials. He also expressed the view that only a small pressure was needed to cause these adhesives to bond to each other. He thought that the experiment showed little dependence on pressure and on temperature.
49. Mr Alkin submitted that the person skilled in the art would not approach the scrutiny of samples in the way that Mr Palmer had done with a magnifying glass. I must say, I think there is some force in Mr Alkin's submission. Mr Alkin also submitted that the fact that Mr Palmer looked for fibre tear showed that it was the right criterion to use for disruption of the base layer, but at the stage he did this Mr Palmer was focused on the unamended patent. I think he simply characterised a failure mode as fibre tear because that is what he saw.
50. Mr Palmer's second test was conducted on 29^th November 2012 at Manchester Metropolitan University. At this stage, Mr Palmer was still unaware of the patent amendment. This test involved using whole mailers, which were closed with finger pressure. The pressures used were described as follows: "Light, medium, high, maximum, lightest". The experiment was conducted using a sophisticated pressure sensor to measure the finger pressure as it went along. The same approach to looking at failure modes was used as in the first experiment. In this experiment, of the 15 tests there was some fibre tear in 14, always at the tamper-evident slits. It was also shown that there was no pressure applied in this experiment with the fingers being used above 420 kPa.
51. Mastermailer submits that this second test of Everseal's is not what the skilled person would do. That is as a result of using the sophisticated pressure pad. Mastermailer submits that experiments like Westmoreland's, or Mr Palmer's first experiment, are the sort of thing that a skilled person would do on reading the patent. Mastermailer supports this by arguing that it is notable that the first experiment Mr Palmer did was like the Westmoreland experiments. I do not accept this latter point as a point of substance. Mr Palmer's conclusion after his first experiments was that more was needed. In any case, Mr Palmer's first experiment came after witnessing the repeat of Westmoreland's experiments himself.
52. Everseal submits that the second test is just a test of sealing with finger pressure. That is what the skilled person would do. The refinement of the pressure pad allows us to see in the courtroom what effect it has.

The experts' opinions.

53. Mr Morris's view can be summarised as follows. Disruption of the base material means fibre tear. Disruption of the adhesive means disruption sufficient to prevent or seriously impair the function of the adhesive. He supported the Westmoreland experiments. They showed that mode 1, that the sample can be resealed, showed a reversible seal, and that is what happens at low pressure. High pressure gives a better seal, and the seal would be irreversible only if the original pressure was above 1 MPa.
54. Mr Deacon submitted, from Mr Morris's evidence, that certain passages from Mr Morris's evidence were inadmissible. This submission is set out in paragraph 22 of the revised main skeleton argument. In my judgment, it is clear that Mr Morris's views, on the meaning of plain English, are not admissible. There were no technical terms in use in this case. But bound up in the passages referred to by Mr Deacon was evidence which was admissible. I will quote the first example. This is at paragraph 22(1) of Mr Deacon's revised main skeleton, referring to paragraph 27 of Mr Morris's report:

"I think that the skilled person would understand 'disruption of the base material' in this context to mean fibre tear. As I have explained, this was a well-known practical measure of bond strength in the industry at the time."

55. The second sentence is admissible evidence, and I have taken it into account. The approach I propose to take to Mr Deacon's objections is that I will not declare any parts of Mr Morris's evidence as inadmissible, but I will bear in mind that his views on the meaning of ordinary English words are not relevant.
56. An important matter arose in the cross-examination of Mr Morris. In his statement, he said the following at paragraph 20:

"Between about 1998 and 2002, while at Laser Image, I developed a fifth type of mailer for Stephen Black, the eventual founder of Mastermailer. This type of mailer used dry, non-tacky contact adhesive but could, nevertheless, be sealed manually; ie, combined the best features of both pressure seal and pressure-sensitive mailers. Mastermailer started selling this product in around 2002. In fact, I moved from Laser Image to Mastermailer to oversee its manufacture."

57. Here, Mr Morris was saying that when he devised his mailer using a dry non-tacky adhesive, it combined the best features of the two earlier known adhesives. They are the pressure seal and the pressure-sensitive adhesives; ie, the high-pressure one and the release-layer one. Given that he had emphasised that both known adhesives produced a seal which was difficult, if not impossible, to re-separate without causing fibre tear, a fair reading of this passage is that his dry non-tacky adhesive produced the same sort of seal, albeit manually. The point, of course, is that this means that the manually-resealable product that he produced would have sealed irreversibly to Mastermailer's standard of what "irreversibly" means; ie, fibre tear. That matters because this development work is the work that led directly to the products alleged infringe in this case. After 2002 until 2007 they were sold without anti-tamper strips, and then in 2007 they mostly had anti-tamper strips, save for a product called TAS, which is the product actually tested in the Westmoreland experiments.
58. Mr Morris was cross-examined about this. Although he did not say it, my distinct impression of him was that he immediately realised the importance of this obvious inference, and realised it was inconsistent with his other opinions and the thrust of Mastermailer's case. His answers were given in that light.
59. In cross-examination, Mr Morris accepted that pre-2007 products were secure, but on the question of irreversibility, he said: "It depended on the process. In principle, yes, but there were always variables." In answer to a similar question, namely, "Did the adhesive referred to in paragraph 20 of his report have the feature claimed?" he said: "No. It depends on the pressure. Very heavy finger pressure probably would get fibre tear." Then, again, when asked about security without the anti-tamper strips, he said: "They still have security in question. It depended on the pressure.", "Finger pressure?" was the question, and his answer was: "Excessive, yes." In other words, he was saying there that excessive finger pressure would produce an irreversible seal.
60. Mr Alkin emphasised that Mr Morris's answers given in cross-examination only accepted that fibre tear took place at excessive finger pressure. Mr Alkin submitted that we did not know what excessive finger pressure was. It could be 500 kilopascals or more. He also submitted that Mr Morris's evidence of this was anecdotal and could not be relied on.
61. I do not accept Mr Alkin's submission as a characterisation of Mr Morris's evidence. It was not anecdotal. He is in a position to know about these products. His report, taken at face value and read fairly contained an implicit acceptance that the relevant product sealed to the same general extent as the known adhesives; ie, they could be manually sealed and that re-separation without tearing was difficult. My distinct impression of his answers in cross-examination was that he saw the problem but realised that he could not go too far with a denial, so he stuck to a line that "excessive" finger pressure was required. I do not accept that evidence. My impression of his evidence, as a whole, was that the products he designed, without the anti-tamper strips, were secure and sealed to the same degree, at least, as the prior pressure-sensitive adhesives (which were somewhat weaker than the pressure-seal adhesives, but still plainly irreversible).
62. I also rely on the reality of Mastermailer's position. The purpose of the concept of irreversibility ties in closely with the purpose of these of these business forms. It is to make products secure by discouraging tampering. The products are pointless unless normal customers, on a large scale, can manually seal them securely. Mastermailer was selling secure business forms without anti-tamper strips supplied by Mr Morris's company from 2002 to 2007. I infer that, in general, Mastermailer's mailers, as they were in 2002 to 2007 without anti-tamper strips, sealed irreversibly under hand pressure on a consistent basis. I also infer that, in general, Mastermailer's mailers, after 2007, with anti-tamper strips, also sealed irreversibly when sealed manually on a consistent basis. By "manually", I mean by the vast bulk of the staff at Mastermailer's customers. There was no suggestion that special measures were needed to seal Mastermailer's mailers in order to make tampering evident.
63. I should mention the TAS sample. That is the sample tested by Westmoreland for Mastermailer. It represented a very small fraction of Mastermailer's product line, something like 50,000 per year for TAS as compared with two million products per month, in general. The reason why the TAS product does not have an anti-tamper strip is only because it has not been economic so far to change its cutting die. When the die is changed, the TAS will be given anti-tamper strips.

Mr Palmer's evidence

64. His position was that the disruption of the base material did not need fibre tear. He included ink being pulled off the substrate and wrinkling. He thought both were examples of disruption of the base material. I have rejected the former. I accept the latter, although it must be a matter of degree. He saw disruption of the adhesive surface in all the samples of the witnessed repeat. He thought that the small areas tested in the Westmoreland experiments were too small to be representative. They may react differently when peeled apart in comparison to the reaction of a complete mailer. He said that his experiments – that is his latter experiments – indicate that manual pressure above 500 kilopascals was not possible for an average human. That is in paragraph 2 of his second report. It was not undermined in cross-examination. Mr Alkin submitted that I should be cautious in accepting it since it is based on Mr Palmer's test. I am prepared to accept that, in all probability, it is possible for some, probably only very large or very strong people, to apply a higher pressure if they really try, but I accept Mr Palmer's evidence as to the general position of normal people.
65. In cross-examination, Mr Palmer accepted that he had not challenged the assessment in Westmoreland's experiments that the samples could be resealed if the Westmoreland operator said that they could be, but he maintained his position on disruption of the adhesive layer. He said that once adhesive is removed from the base material, it will not re-stick to that base material because the adhesive only sticks to itself.

Does the Mastermailer mailer infringe?

66. First, I have rejected the argument that the anti-tamper strips are irrelevant. The fact that they are not common general knowledge in 1998 does not matter. The claim is to a mailer. The properties claimed must be properties of the mailer or, which is the same thing in this context, properties of the adhesive layer in the context of the actual mailer itself. Accordingly, I do not accept that proving that the TAS product without anti-tamper strips is outside the claim shows that the other products with anti-tamper strips are outside the claim.
67. Second, on technical matters concerning the function of adhesives, I prefer Mr Palmer's evidence to that of Mr Morris. I appreciate that Mr Morris can be said to have had practical experience for many years of using these adhesives in the context of mailers, but he was not an adhesive specialist. Mr Palmer has the expertise in adhesives specifically. I accept Mr Palmer's evidence that these adhesives work by auto-adhesion so that only a small pressure is needed to initiate auto-adhesion – he suggested 1 kilopascal – and that the adhesive force produced is time and temperature dependent, or should be.
68. Third, I was very struck by Mr Morris's evidence in cross-examination. This is a simple mechanical patent. I think that the first thing that any skilled person would do is to ask themselves, "Does the product manually seal to a satisfactory degree?" Irreversibility of the seal is what the person skilled in the art wants, so the fact that Mr Morris's company's products, sold by Mastermailer without anti-tamper strips, clearly were perfectly adequate commercial products prior to 2007 when the anti-tamper strips were included, is evidence that raises a fairly strong inference that they are in accordance with the invention in the patent. They are the kind of products the claim was meant to catch.
69. This provides the context for the experiments relied on by Mastermailer. In essence, Mastermailer's experiments are trying to establish that Mastermailer's product does not work satisfactorily under the sort of low pressure available manually, even though Mastermailer markets the product as a mailer to be sealed by hand. I view that with suspicion. The results of the Westmoreland experiments appear to show that 1 megapascal's pressure is needed before one of Mastermailer's products can be sealed irreversibly. In my judgment, these tests are not representative of reality. Mr Palmer's opinion was that the small areas tested in the Westmoreland experiments were too small to be representative. I accept that opinion. It follows that Mr Palmer's similar tests on small areas, done after the witnessed repeats, are also not representative, but that is not inconsistent with Mr Palmer's evidence since he expressed concern about the small area tested in that test as well.
70. Mr Alkin said that the patent claim had not sought to claim manual sealing but had set a numerical limit, and that had to be taken account of. He said that the test a skilled person would conduct would be like the Westmoreland tests and Mr Palmer's first test, and those tests, submitted Mr Alkin, show non-infringement. I agree that the claim is not a claim to manual pressure. It is a claim with a numerical limit. I agree that that cannot be ignored. However, I think a fair-minded skilled person or team would approach the question of whether the products fell within the patent, first, by sealing them by hand and then pulling them apart. If the products sealed satisfactorily, by which I mean irreversibly, in this test, then the skilled person would think it was likely that he was within the claim. Manual sealing is what the patent is concerned with providing, albeit that the claim is delimited by reference to a numerical pressure. The skilled person would then need to devise a test to check the numerical limit. However, if a particular experiment when carried out showed results which were as inconsistent with the practical manual reality, as the tests in this case carried out by Mastermailer, then the person skilled in the art would not accept that that experiment was fair, without much more care, attention and, importantly, further testing, than has happened here. The skilled team includes someone with the expertise of the same kind as Mr Palmer's. I have accepted his opinion that the Westmoreland tests' small sample was not representative. That is what the skilled team would think.
71. It seems to me, therefore, that, in the situation I have described, at least whole mailers would be tested. That has not been done by Mastermailer. I think there was much to be said for Mr Alkin's submission that no skilled person would think that he had to do an experiment involving a sophisticated pressure sensor, but it is not necessary to resolve that question conclusively. However, Mr Alkin's point does not mean that the results of Mr Palmer's second tests are of no significance in this case. From the experiment we can see what happens when a Mastermailer product with anti-tamper strips is sealed with finger pressure. That is enough to put the skilled person on their guard about a test like Mastermailer's, which purports to show the opposite. We can also see from Mr Palmer's second test that finger pressure is usually much less than 500 kilopascals. That is sufficient to raise serious questions about Mastermailer's experiments, even leaving aside the reality of this case that Mastermailer's products are secure hand sealable mailers.
72. In summary, first, I find that the anti-tamper strips have to be taken into account. I am not satisfied that Mastermailer's products with anti-tamper strips do not infringe. The only evidence about them is, really, both of Mr Palmer's experiments as well as the obvious inference from Mastermailer selling them as secure, hand-sealable mailers. I will grant no declaration on this ground alone.
73. Second, regardless of the anti-tamper strips, I am not satisfied that Mastermailer's experiments conducted by Westmoreland establish that the products tested do not infringe the claim. Those products are the TAS products without anti-tamper strips, so there will be no declaration on this ground as well.
74. Accordingly, I find that Mastermailer's claim for a declaration fails, and I will hear the parties.
(For discussion after Judgment, see separate transcript)