Single layer paint samples that appear indistinguishable by colour cannot be asserted to have come from the same source without knowing how common the paint is in the environment. With additional data, it may be possible to estimate the probability of the defendant becoming exposed to an alternative source of the same paint in a restricted time frame and small geographical area. This contextualising of analytical results given a set of conditions is the basis of interpretation, a skill which has developed from a common sense, classical methodology to a more statistically based approach with the application of Bayes' theorem. However, statistical models require data to inform them and there are few published paint data sets.