Information on materials and procedures of painters of the past can be gained from the latest examinations of a painting and its materials and from documentary sources, the change of meaning of which is of prior interest to historians of technical art. This paper is an empirical and theoretical examination of the relationships between the two main early medieval collections of craft recipes, the Compositiones Lucenses and the Mappae Clavicula. The primary aim of this work is to criticise the current prevalent meaning of the concept of Mappae Clavicula, and to show that its tradition does not include that of Compositiones: these two traditions, despite sharing two sets of manuscripts, result in two appreciably different texts. The first edition of the eighth to ninth centuries recipe book Compositiones Lucenses (Lucca, Biblioteca Capitolare, 490) occurred in 1739, and the twelfth century exemplar of Mappae Clavicula's text about one century later (Corning, Museum of Glass, Phillipps 3715, or Corning manuscript). In the interwar period and particularly after WWII, the Lucca manuscript was predominantly considered to be a member of the Mappae Clavicula tradition, which was regarded as second only to Theophilus's De diversis artibus, as a written source for the study of medieval technology. 'Compositiones Lucenses' and 'Mappae Clavicula' are taxonomic concepts for the classification of medieval manuscripts and texts, the meanings of which we redefine in this paper. In contrast to today's prevailing approach, we move the focus from two single manuscripts (Lucca 490 and Corning) to two different traditions of witnesses, and from single texts to collections of texts bound in the same codex. The critical section of the paper concerns the most important interpretations of the notion of Mappae Clavicula, while the positive section draws on three works: the seminal paper by Halleux and Meyvaert (1980s), Baroni's first critical edition of Mappae, and the inventory of the manuscripts of the Compositiones tradition by Brun (2010s). In the empirical section we contrast the two traditions and consider two sets of items: twelve manuscripts reveal the internal structure of the Compositiones Lucenses tradition, and nine codices, which transmit both traditions, shed light on how these traditions differ. As a result of the present research, we show that a significant segment of the Compositiones Lucenses tradition is composed of an aggregation of small recipe nuclei, and that this tradition developed regardless of that of the Mappae. The Mappae Clavicula and Compositiones Lucenses are two distinct textual traditions and not members of a super-corpus.