Paper × 841 mm). A1 is half the size of a sheet of A0 (i.e., 594 mm × 841 mm), such that two sheets of A1 placed side by side are equal to one sheet of A0. A2 is half the size of a sheet of A1, and so forth. Common sizes used in the office and the home are A4 and A3 (A3 is the size of two A4 sheets). The density of paper ranges from for tissue paper to for some speciality paper. Printing paper is about . Paper may be classified into seven categories: Some paper types include:
Paper football way that an American flag is folded to form a triangle. First the paper is folded lengthwise two or three times to form a long rectangle. Then it is repeatedly folded in a diagonal fashion, forming a triangle. Finally, the end of the strip is tucked into the last fold, securing the final paper football in a triangular shape. In the absence of paper, sugar packets, matchbooks, and foil-wrapped cookies have also been used to substitute for a ball. Many variations of the game exist, but generally paper football games vaguely emulate American football. The two opposing teams (usually two