to the absence of textual sources, our understanding of the earliest color printing techniques and their dissemination across Europe has been based on the visual analysis of the printed material itself, with reference to traditional hand-press techniques. But printers’ inventories included frisket sheets as early as 1514, 4 and it has long been widely accepted that they were commonly used for color printing from the fifteenth century. Nevertheless, their construction and use in the fifteenth and sixteenth centuries could be only hypothesized until 2000, when Margaret Smith published a scholarly description of the first and hitherto only known early modern artifact of any color printing process in the West: a fragment of an early sixteenth-century frisket sheet that had been used for printing in red, now at St. Bride Library, London. That frisket sheet had been discovered in or before 1903 by Robert Steele, and the brevity and vagueness of Steele’s report proved typical of the few published references to early modern frisket sheets in the twentieth century:“in the cover of an early French binding I have found... a number of vellum masks; showing that red initials were printed from the whole page of type.” 5 He provided no further information. The standard bibliographical handbooks referred to their use for color printing before Moxon (based on visual analysis), but the little that was written about the known objects was incidental. Because research into the early history of the color printing of text typically focused on the number of formes used and impressions pulled, the discovery that the St. Bride frisket sheet is not unique but may be one of hundreds (if not thousands) that still survive opens a new avenue of research. This paper introduces a growing corpus of thirty fragments comprising twenty-three other early modern frisket sheets for color printing.