This book offers the original text in Catalan with a Spanish translation of the manual of dyeing of Joanot Valero, an artisan dyer from Sarrión (in the south of Aragón, close to the border with the ancient realm of Valencia). The manual is a recipe book for the dyeing of wool cloth, with over 100 formulae for the application of dyes and stain removers, plus the treatment of possible health problems among the artesans. There are points in common with the dyeing manuals of the Late Middle Ages in Italy, it but is more practical in nature since the author compiled the recipes for his personal use.