Manifold paper is a lightweight, translucent paper used with carbon paper
to make multiple copies of a document. It is also called tissue paper or onionskin paper.
"Carbonated paper" was invented by Ralph Wedgwood for his "stylographic writer" patented in 1806, but it was only with the advent of the commercial typewriter in the 1870s that it became widely used.
The word manifold means many. It can also be used as a transitive verb meaning to duplicate.