The statutory provisions
Section 213 of the Copyright Designs and Patents Act 1988 provides, so far as material:
“(1) Design right is a property right which subsists in accordance with this Part in an original design.
(2) In this Part “design” means the design of any aspect of the shape or configuration (whether internal or external) of the whole or part of an article.
(3) Design right does not subsist in:
(a) a method or principle of construction,
(b) features of shape or configuration of an article which:
(i) enable the article to be connected to, or placed in, around or against, another article so that either article may perform its function, or
(ii) are dependent upon the appearance of another article of which the article is intended by the designer to form an integral part, or
(c) surface decoration.
(4) A design is not “original” for the purposes of this Part if it is commonplace in the design field in question at the time of its creation.”
As many judges have commented, section 213 is notoriously difficult to understand. As Jacob LJ put it in Dyson v Qualtex  RPC 31: “It has the merit of being short. It has no other.”
A person who is entitled to unregistered design right has the exclusive right to reproduce the design for commercial purposes by making articles to that design or by making a document recording the design: 1988 Act s. 226 (1). Section 226 (3) provides:
“Reproduction of a design by making articles to the design means copying the design so as to produce articles exactly or substantially to that design”
The word “article” is not further defined, but section 260 (1) provides:
“The provisions of this Part apply in relation to a kit, that is, a complete or substantially complete set of components intended to be assembled into an article, as they apply in relation to the assembled article.”
Thus as Mummery LJ explained in Farmers Build Ltd v Carier Bulk Handling Materials Ltd  RPC 461:
“The purpose of copyright and of design right is not to protect the “novelty” of the work against all competition it is to provide limited protection against unfair misappropriation of the time, skill and effort expended by the author of design on the creation of his work.”
What is a design?
In Rolawn Ltd v Turfmech Machinery  RPC Mann J pointed out that:
“It is important to isolate the design in respect of which protection can be properly claimed, and it is vital to ensure that it falls within the definition of design. The Act defines design as “any aspect of the shape or configuration of the whole or any part of an article”, and the right cannot exist until there is an embodiment of the design in an article or in a design document. This combination of features means that design right is confined to what one can actually see in an article – either the physical article or a drawing.”
Design right does not therefore protect ideas. Ideas are protected by patent law. It follows, therefore, that Virgin Atlantic are not entitled to claim design right for the general concept of an inward facing herringbone arrangement of seats: Kleeneze Ltd v DRG (UK) Ltd  FSR 399. Mr Meade accepted this as a matter of law (at least at this level in the judicial hierarchy) and confirmed that he was not putting Virgin Atlantic&aposs case on that basis. Nor, I think, does Virgin Atlantic claim design right in the general concept of an inward facing herringbone where the angle of installation of the seats exceeds 18o.
What is an aspect of the shape or configuration of an article?
It is, of course, plain from the words of section 213 itself that design right can be claimed for the design of part of an article. A teapot spout or a teapot handle are frequently cited examples. An aspect of the design is something that is discernable or recognisable (not necessarily to the naked eye) but it need not be visually significant: A Fulton Co Ltd v Totes Isotoner (UK) Ltd  RPC 16, ?? 31.
One of the real difficulties of section 213 is that the claimant may select a part of the article and claim design right for that part only. The courts have recognised this possibility since the early days of design right. In Ocular Sciences Ltd v Aspect Vision Care  R.P.C. 289, 422 Laddie J said:
“the proprietor can trim his design right claim to most closely match what he believes the defendant to have taken. The defendant will not know in what the alleged monopoly resides until the letter before action, or, more usually, the service of the statement of claim. This means that a plaintiff’s pleading has particular importance. It not only puts forward the claim but is likely to be the only statement of what is asserted to be the design right.”
Unregistered design right is, of course, not a true monopoly: it merely prevents copying. But otherwise that statement of the law is correct, subject to the gloss given by Jacob LJ in A Fulton Co Ltd v Totes Isotoner (UK) Ltd :
“I do not fully go along with Laddie J.&aposs suggestion that what the proprietor can do is to “trim his design right claim”. It is not really a question of “trimming”it is just identifying the part of his overall design which he claims has been taken exactly or substantially. And although Laddie J. was right in saying that the defendant will not know in what the alleged (my emphasis) monopoly resides until the letter before action or the claim form, that does not mean the defendant does not know where he stands before then. The man who copies a part of an article, exactly or substantially, will know what he has taken. It is true that it will be for the designer to formulate his claim properly in any proceedings, but the subsistence of his rights does not depend on how he frames his claim.”
In a sense it is of course true that a man who copies part of an article will know what he has taken. But similarities between the design relied on and the allegedly infringing article are often relied on to raise the inference of copying which the defendant must then rebut. There is a danger that the ability of the claimant to select parts of his design which are small in comparison to the overall article will give rise to a distorted impression of what the defendant has done which comes close to reversing the burden of proof. This concentration on relatively minor aspects of the overall design also had a tendency to make some of the witnesses more defensive than they might otherwise have been. There is another point to be made here. Virgin Atlantic&aposs pleaded case did not rely on designs as recorded in design documents. Rather they relied upon the designs as embodied in the actual UCS. As it was put in the pleading:
“Insofar as there are any identifiable difference between the design drawings herein referred to and the Designs as embodied in the earliest commercially available UCS seating system the Claimant relies on the latter.”
Thus what is alleged to have been copied is the real life version of the UCS and what is being compared is the real life version of the UCS with the real life version of Solar Eclipse. This is important because the plans, elevations, and isometric drawings, being only two dimensional, can give a distorted picture of reality.
What must be established is that the design in which design right subsists has been copied so as to produce “articles exactly or substantially to that design”. Two points arise. First, although the Act allows design right to subsist in (and be claimed for) part of an article, the definition of reproduction speaks only of making “articles”. There is, therefore, a linguistic mismatch between subsistence of design right and the right that it confers. But it must obviously have been Parliament&aposs intention that if design right subsisted in part of an article (e.g. the teapot spout) the right would be infringed by incorporating a copy of that spout in another teapot, even if the infringing spout is not itself a whole article. Second, even if the design has been copied, the infringing article must be produced “exactly or substantially” to the copied design. Mere similarity is not enough.
In C& H Engineering v F Klucznik & Sons Ltd  FSR 421 Aldous J said:
“Under section 226 there will only be infringement if the design is copied so as to produce articles exactly or substantially to the design. Thus the test for infringement requires the alleged infringing article or articles be compared with the document or article embodying the design. Thereafter the court must decide whether copying took place and, if so, whether the alleged infringing article is made exactly to the design or substantially to that design. Whether or not the alleged infringing article is made substantially to the plaintiff&aposs design must be an objective test to be decided through the eyes of the person to whom the design is directed.”
Although, at least in theory, two separate criteria must be satisfied viz. copying and making articles exactly or substantially to the copied design, it is not easy to conceive of real facts (absent an incompetent copyist) in which a design is copied without the copy being made exactly or substantially to the copied design. In practice, if copying is established, it is highly likely that the infringing article will have been made exactly or substantially to the protected design. If copying is not established, then whether the article is the same or substantially the same as the protected design does not matter. However, similarity in design may allow an inference of copying to be drawn.
Copying: the approach to the evidence
I find helpful the observations of Lord Millett in Designers Guild Ltd v Russell Williams  1 WLR 2416 considering the question of copying in relation to an artistic work:
“The first step in an action for infringement of artistic copyright is to identify those features of the defendant’s design which the plaintiff alleges have been copied from the copyright work. The court undertakes a visual comparison of the two designs, noting the similarities and the differences. The purpose of the examination is not to see whether the overall appearance of the two designs is similar, but to judge whether the particular similarities relied on are sufficiently close, numerous or extensive to be more likely to be the result of copying than of coincidence. It is at this stage that similarities may be disregarded because they are commonplace, unoriginal, or consist of general ideas. If the plaintiff demonstrates sufficient similarity, not in the works as a whole but in the features which he alleges have been copied, and establishes that the defendant had prior access to the copyright work, the burden passes to the defendant to satisfy the judge that, despite the similarities, they did not result from copying.
Even at this stage, therefore, the inquiry is directed to the similarities rather than the differences. This is not to say that the differences are unimportant. They may indicate an independent source and so rebut any inference of copying. But differences in the overall appearance of the two works due to the presence of features of the defendant&aposs work about which no complaint is made are not material. In the present case the disposition of the flowers and (except in one instance) the colourways of the defendant’s design are very different from those of the plaintiff’s design. They were not taken from the copyright work, and the plaintiffs make no complaint in respect of them. They make a significant difference to the overall appearance of the design. But this is not material where the complaint is of infringement of copyright and not passing off.”
Nevertheless it is also important to bear in mind Mummery LJ’s warnings in Farmers Build (at 481 and 482):
“Substantial similarity of design might well give rise to a suspicion and an allegation of copying in cases where substantial similarity was often not the result of copying but an inevitable consequence of the functional nature of the design. Copying may be inferred from proof of access to the protected work, coupled with substantial similarity. This may lead to unfounded infringement claims in the case of functional works, which are usually bound to be substantially similar to one another.
[The court] must not forget that, in the field of designs of functional articles, one design may be very similar to, or even identical with, another design and yet not be a copy: it may be an original and independent shape and configuration coincidentally the same or similar.”
However, as in any case where there are factual presumptions and shifting evidential burdens, the question of copying is in the end a question of fact and one which must be proved by the claimant on the balance of probabilities.
In considering the question of copying the function of the experts is not to evaluate the factual evidence, but to point out to the court the similarities and differences between the design and the alleged infringement and the significance of those similarities and differences, so that the court can come to a view on whether they are such as to lead to a rebuttable inference that the defendant has copied the claimant&aposs design. Both sides of the equation are important. An expert ought to deal both with the similarities between the design and the alleged infringement and also with the differences. To concentrate on the similarities alone or on the differences alone gives an unbalanced view.