Hi sarah
Let's take the trade mark issue first. Generally speaking trade marks have to be registered before they gain legal protection, which means that this is mainly confined to company or product names and logos. Occasionally some slogans (things like "Have a break, Have a Kitkat") get registered along with more esoteric qualities such as colours (the red soles of Christian Laboutin shoes for example). But unless your cuff links etc use any such registered marks, your use will not amount to trade mark infringement. And even if you do use a registered mark, or a substantial part of it, that won't necessarily amount to infringement if it is unlikely to confuse anyone as to the origin of the goods. A major factor in this last point is the categories of product the trade mark has been registered for. For example unless Marvel have registered a super hero which you have used, in
Class 14 (Personal jewellery) they face an uphill battle in trying to show confusion, whereas if you were selling magazines the proximity of the two products in the marketplace would make the possibility of confusion much greater. That's why we can have the same trade mark used by Apple the phone and computer maker and Apple the record label.
There is a body of common law which relates to something called
passing-off, which may be applied where a trade mark (or similar feature) has not been registered but has nonetheless become closely connected to the goodwill in a company or product etc. This is much more likely to cause you problems, because clearly one of the reasons you wish to use parts of these comics is the association with the original item. I suspect that the appeal of the cuff links is greatest among fans of the comics who recognise and value the connection. However in order to prove passing off, a claimant needs to show that he has goodwill in his product, that there has been misrepresentation leading to confusion in the minds of customers as to the true origin of the goods, and that as a result damage has been caused to the claimant. Factor number three - damage - would be quite hard to show in your case, because clearly your sales in no way undermine the saleability of the comics themselves. The best way to resist factor number two - misrepresentation - is to clearly announce to your customers that your products are not licensed or approved by DC or Marvel Comics etc. There is little you can do about factor number one - goodwill - as that undoubtedly exists amongst the fans of the comics.
Turning to copyright, things are much clearer. As you are not copying but re-purposing the original works, you are covered by something called the
exhaustion of rights. This doctrine says that once something has been legitimately sold, the rightsowner's ability to control what happens to the disposal of the work is extinguished. For example if you buy a first edition of a rare book, and subsequently re-sell it for a greater amount than you paid for it, the copyright owner has no come back. Equally, if you decide to give the book away, or burn it, that is also outside the control of the copyright owner.
One small twist in this otherwise straightforward doctrine came about recently in the decision of the Court of Justice of the European Union (CJEU) in a case called
Art & Allposters International BV v Stichting Pictoright. This case involved a company (Allposters) which bought posters featuring old, out-of-copyright works of art, and by some chemical process transferred the printed image onto a canvas background, so that the finished product looked like an oil painting. Pictoright owned the copyright in the original posters and complained that this process infringed their copyright, not least because Allposters was selling their canvases for many times the cost of the posters. The CJEU said that this was indeed infringement and that the exhaustion of rights doctrine did not apply because Allposters had changed the tangible medium which comprised the copyright work (ie the paper substrate of the poster). This decision has been criticised by a number of people because, firstly, it makes the law less clear, and secondly because the court took into account the greater value of the secondary work, which should really be irrelevant to their decision.
If you do not destroy the medium on which the images you use are carried, this court decision should not effect what you want to do. However it does introduce a level of uncertainty which was not there before.