From 1984–1989 he was Director of Typography for Adobe Systems where he conceived and implemented Adobe’s typographic program including the Adobe Originals.
In 1990 he founded Stone Type Foundry Inc., now located in Rumsey, California (http://www.stonetypefoundry.com).
The Foundry has produced a variety of prize-winning typefaces as well as custom type designs.
As a teacher Mr. Stone has conducted many calligraphy and typography classes at several institutions. Over the past few years, Sumner has taught several different courses and type workshops in the Type@Cooper program at Cooper Union.
He is the author of books, and many articles about typography and typeface design, and has lectured widely on these topics.