Japanese angelshark is eaten and the rough skin is made into a type of leather called shagreen for use in wood finishing. Angel sharks in general are highly threatened by commercial trawl fisheries due to their susceptibility to capture and low rate of reproduction, and angel shark species elsewhere are known to have declined markedly under fishing pressure. Trawling activity in the Yellow Sea and other parts of the northwestern Pacific is intense and, coupled with pollution, has had a serious impact on the local ecosystem. The Japanese angelshark population is suspected to have declined by up to 50% or more under
Shagreen or if the technique was developed separately. In the 17th and early 18th centuries, the term "shagreen" began to be applied to leather made from sharkskin or the skin of a rayfish (probably the pearled ray, "Hypolophus sephen"). This form is also termed sharkskin or galuchat. Such skins are naturally covered with round, closely set, calcified papillae called placoid scales, whose size is chiefly dependent on the age and size of the animal. These scales are ground down to give a roughened surface of rounded pale protrusions, between which the dye (again, typically green vegetable dye) shows when the material