Patent ID: 8363269

Claim:
An image forming apparatus comprising: an image forming unit which forms an image in accordance with image information; a designation unit which designates a type of a printing medium; an addition unit which adds identification information to the image information if the type of the printing medium designated by said designation unit is not an overhead transparent (OHT) sheet, and does not add identification information to the image information if the type of the printing medium designated by said designation unit is the OHT sheet; and a detection unit which detects the type of printing medium conveyed to said image forming unit; and a setting unit which sets an image forming condition in said image forming unit according to the type of the printing medium, wherein said setting unit changes the image forming condition to a lower density of the image formed by said image forming unit if the type of printing medium designated by said designation unit is the OHT sheet and the type of printing medium detected by said detection unit is a type of sheet different from the OHT sheet.