Thin and transparent paper with red copybooks is called copy paper. A thin layer of paper on a copybook is not only called copy paper, but also called copying paper. As the name implies, this kind of paper is used by beginners to copy copybooks. The thicker one is called sulfuric acid paper, which was originally used to print pictures.
Ordinary stationery stores sell them, and they are not expensive.
Copywriting is a model copied by people who study calligraphy, mostly stone rubbings, woodcuts or photocopies of famous artists who use ink.