 Matthew Carter has cited his 1966 Snell Roundhand typeface as deliberately designed to replicate a style of calligraphy hard to simulate in metal.An additional development enabling more sophisticated script fonts has been the release of the OpenType format, which most fonts are now released in.This allows fonts to have a large character set, increasing the sophistication of design possible, and contextual insertion, in which characters that match one another are inserted into a document automatically, so fonts can convincingly mimic handwriting without the user having to choose the correct substitute characters manually.