In recent years, the commercial catalogues of businesses that produce teaching aids -- which, prompted by the spread of a pedagogical vision linked to activism, first appeared in the second half of the nineteenth century in parallel with the first production of school objects -- have acquired increasing importance as a research source in the field of historical pedagogy. Their versatile nature makes them a rich, varied and precious research tool that can make a considerable contribution to the field of studies related to school materials. The aim of this article is to define the characteristics of this source to subsequently show how recent research grants have been able to offer a first instance of comparative reflection on the issue. From a review of the data that has emerged, a methodological framework for studying commercial catalogues of teaching aids as a research source is being traced out, with plans for future steps on an international level to reinforce its study.