I understand that 16 paper opening refers to the size of paper, and the specific size is 185mm x 260mm, which is the most common standard size in China. Generally suitable for various purposes, such as offices, schools, magazines, books and so on.
The size of A4 paper is 2 10mm x 297mm, while the size of 16 paper is half that of A4 paper, that is,185mm x 260mm. ..