8. The paper opening size is 260mm & times; 370mm, about the size of two A4 sheets of paper. The opening in the 8-opening paper refers to how many copies a standard sheet of paper is cut or folded. The 8-opening refers to the layout after the whole sheet of paper is folded in half for three times. 8. The difference between open paper, A3 paper and A4 paper. The size of open paper is 260mm & times; 370mm, which is about equal to the size of two 16 opening sheets. The format refers to the size of the book format, that is, how many pages a full open printing paper is cut into.
A3 paper refers to the paper of international general standard A3 specification, with the size of 297mm & times; 420m, A3 paper is twice as large as A4 paper.
The size of A4 paper is 210mm & times; 297mm, A4 and A3 paper are commonly used for printing and copying documents. （8KaiZhiDuoDaCheCunDaXiao）