This part of ISO 3272 specifies reduction ratios, enlargement ratios, sizes of enlargement and the resulting image sizes for recording on 35 mm unperforated microfilm technical drawings and other drawing office documents, such as architects' plans, calculation notes, specifications, vocabularies and parts lists. This part of ISO 3272 applies to the microfilming of documents no larger than A0 with dark lines and characters on a light background, preferably prepared in accordance with ISO 5457 and ISO 6428. It may also apply to sizes other than those specified in ISO 5457, provided they are no larger than 912 mm × 1 230 mm and can be accommodated within a single frame of 35 mm microfilm, as specified in this part of ISO 3272. This part of ISO 3272 does not apply to images created by a COM device.