It is possible to determine if a particular document was written entirely on one typewriter, or if parts of it were written on another. The design of characters of the typescript, measurement of both horizontal and vertical spacing and of the height of the letters can point to fraud, tampering with the document, or misdating. Individual characteristics of typewriters can identify a particular machine used for a given document in question. These characteristics include type face defects, platen size and platen defects, lateral or vertical misalignment, and the uniformity of ribbon characteristics and pressure on the keys. Ribbon impressions can also help to determine if a document was improperly dated. If other documents dated before and after the document in question do not show the same basic impressions, it can be assumed that the document was misdated. Figures are included.