Substantial part
Copyright Protection

In the context of copyright law, whether a substantial part has been taken is judged by reference to the copied work, rather than the amount that is reproduced in the infringing work. A substantial part is assessed qualitatively - by reference to the important aspects of the original work. The quantity of the material copied may be taken into account however it is not a determinative factor. The amount of copying therefore may be very small with reference to the overall size of the copyright work.

The test takes into account different factors, depending upon the different type of copyright work alleged to have been infringed.

In order to make out a successful claim for copyright infringement, the claimant must prove that the defendant copied the entire copyright work verbatim or a 'substantial part' of a copyright work.