An improved indicia disc for use in association with phototype setting apparatus includes a rigid glass support plate and a flexible photographic film disc carrying a plurality of fonts of alpha numeric characters. The flexible film disc is held against movement relative to the support plate by atmospheric pressure against an outer surface of the film disc. To mount the film disc on the support plate, they are rotated together at a relatively high speed about their central axes. As they are rotated, centrifugal force expels the atmosphere from between the film disc and support plate. Atmospheric pressure against the outer side of the film disc is then effective to press it securely against the support plate. In one embodiment of the invention a one-piece film disc is utilized. In another embodiment of the invention a two-piece film disc is utilized to provide greater flexibility of choice in associating various fonts of characters.