Patents that merely repeat pre-existing ideas are invalid – there has to be something novel about an invention to secure patent protection. However, that does not mean that developments based on the work of others cannot themselves be novel and inventive. Provided such developments are not obvious, patent protection may be available. The High Court made that point in finding that a type of glass fibre merited patent protection.

The European patent had been registered by a company and specified a formula for glass fibre that could be produced at relatively low temperatures but had sufficient strength to reinforce other materials. A second company challenged the patent in an attempt to clear the way for its own planned imports of glass fibre products to be manufactured by essentially the same method.

The formula was said to bear marked similarities to another that had already been patented in the USA (the prior art) and the second company argued that the relevant patent thus lacked novelty and inventiveness. The prior art was reproduced in a standard text on glass manufacturing that was likely to have been read by any expert in the field and was given as a comparative example in the specification for the patent itself.

The Court acknowledged that there was some overlap between the patented formula and the prior art. However, the former represented a significant development of the latter and offered distinct technical advantages that were not obvious. The prior art did not give an individualised description of any glass fibre that fell within the claims of the patent. In those circumstances, the patent was valid and had been infringed by the second company.