Lesson 1: Drafting Equipment – Tools And Materials
American National Standards Institute (ANSI)
In the drafting field there is one recognized sizing system for drawing sheets. This was established and is promoted by the American National Standards Institute (ANSI) in an attempt to standardize sheet sizes in the United States. According to ANSI (American National Standards Institute) in the United States an 8.5 x 11 inch piece of paper is an architectural "A" size sheet (figure 1). This is typically referred to by letter size. The "B" size sheets are 11 x 17 and are typically referred to as a "tabloid" size sheet of paper. The "C" size sheets are 18 x 24 inches and the "D" size sheets are 24 x 36 inches. Most drafting for interior design purposes is done on the B, C, and D size sheets. The decision for choosing a size should be based on project requirements, the scale of the drawings, and the scope and size of the final structure. Trace and vellum may be purchased on rolls that require sizing the paper properly. Trace may be sized by measuring the length needed and using a straight edge, T-square, or parallel rule to rip the paper off of the roll. Trace rips easily and slightly rough edges are expected. Vellum from a roll should be measured to its proper length and then using a straight edge and a knife on a proper cutting surfaces trim the paper to its proper length. Scissors should never be used in cutting trace or vellum. Some areas of the construction industry have adopted this system, but the majority have not, simply because the sizes just do not accommodate larger objects like buildings and bridges. Other disciplines have adopted the ANSI system (Figure – 2) because it is based on a standard 8.5" x 11" sheet of paper. Surveyors, for example, prefer it because they can fold their maps down to 8.5" x 11" size to be filed with accompanying legal documents. . The first sheet in the ANSI system is a standard 8-1/2" x II" sheet of paper. That size is doubled four times to create the five standard sheet sizes. Each size is given a reference letter for easy identification as follows:
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