Tricks of the Medieval Trades:

The anonymous Trinity Encyclopedia (translated here from Middle English for the first time) is a collection of unusually detailed 14th century English craft recipes, collected from several individuals and from a number of written sources, for manufacturing pigments, dyeing, preparing skins and furs, imitating expensive imported leathers, counterfeiting semi-precious materials, ‘multiplying’ (adulterating) verdigris, and for making soaps and confectionery. In many cases, the recipes attempt to codify and make explicit the practical knowledge of the craftsmen, conveying it by means of tips, clues, indicators of progress, tests for quality of materials, tests for progress, and tests for completion.