A fluid terminology was used in antiquity to refer to scientific or philosophical writings that, in some respects, may be equated with what one would call today a handbook or manual. In particular, this paper will explore a group of treatises that may be counted as examples of ancient encheiridia, a Greek term that could mean ‘hand-knife’, ‘handbook’ and even ‘napkin, towel’. All these meanings have something to tell us about the nature and the history of ancient encheiridia, some of which can be identified with well-known pieces of Graeco-Roman literature. However, the spectrum of ancient encheiridia can be further enlarged by exploring sources that are often neglected. After giving an up-to-date overview of ancient ‘handbooks’, the article will discuss the term encheiridion in Graeco-Egyptian alchemical literature. In fact, fresh textual investigations of the Syriac tradition of Zosimus of Panopolis point to the circulation of ancient recipe books that bore this title. On the one hand, this investigation will shed new light on the tradition of other important collections of alchemical recipes, such as the medieval Mappae clavicula. On the other, it will highlight some strategies that ancient alchemical authors developed in selecting, reorganizing and legitimizing earlier alchemical recipes.