Impact is a realist sans-seriftypeface designed by Geoffrey Lee in 1965 and released by the Stephenson Blake foundry. Its ultra-thick strokes, compressed letterspacing, and minimal interior counterform are specifically aimed, as its name suggests, to "impact". Impact has a high x-height, reaching nearly to three-quarters the capital line. Ascenders are short, and descenders even shorter. The face is intended for headlines and has only limited use in text applications. The face bears comparison with the similarly designed, but narrower, typeface Haettenschweiler, the Letraset face Compacta, and the Linotype face Helvetica Inserat.
In July 2010, Ascender Corp introduced an enhanced version of Impact. It included extensive OpenType typographic features designed by Terrance Weinzierl and Steve Matteson.