An under-exploited role for psychology in trademark law is the testing of explicit or implicit judicial assumptions about consumer behaviour. In this paper we examine an assumption that is common across Commonwealth countries, namely, that similar packaging is unlikely to cause consumer confusion provided the brand names are dissimilar. We began by selecting branded products commonly found in supermarkets. For each existing brand we created two novel (fictitious) brands with highly similar packaging to the existing brand. One of these ‘lookalike’ products had a similar name, the other a dissimilar name. Across two yes/no and one forced-choice experiments using photographs of the real and fictitious products we looked at false recognition rates. Contrary to the judicial assumption participants largely ignored the brand names when making their decisions based on memory. It was only when the pictures of the products were placed side-by-side (in the forced-choice task) that they paid the brand name any significant attention.