Paper marbling, sometimes called ebru, is a method of transferring an aqueous design onto paper or a porous material, often cardboard. The result is a true monotype, meaning that each print is one-of-a-kind. Although the term "Turkish marbling" is sometimes used to describe the practice, Turkish people were not the only ones to develop paper marbling. It's been traced back to 986 CE in east Asia. The credit to Turkey is likely because many Europeans would first encounter the practice in Istanbul. These Europeans collected the paper into "books of friendship", similar to a modern autograph album. Today, marbled paper is used primarily for stationary, book making, and collaging.