Tuff began with Magma. Set as text, they appear to be similar and are quite comfortable as typographic companions. The child-safe softness of Tuff owes something to the letterforms of the earliest extant Greek Manuscript, The Persae by Timotheos in the 4th Century BC. It is beholden to Morris Fuller Benton's original Souvenir, and its revival by Ed Benguiat. My own Stone Informal was also an influence.
Sumner Stone worked together with Bob Ishi of Adobe to create the Stone family fonts, which appeared in 1987. Coincidentally, ishi is the Japanese word for stone, which precluded any squabbling about whose name the font would carry. The family consists of three types of fonts: a serif, a sans-serif and an informal style. The Stone fonts are very legible and create a modern, dynamic impression.