Kozo (mulberry) is a traditional washi fiber used to produce exceptionally strong archival papers. ‘Kozo Thick White’ is recommended for fine art photography, giclee prints, museum quality reproductions, scrolls, etc…It is great for images that are intended to backlit, wrapped over frame and other applications where you need a very strong yet semi-transparent paper. (Optical Brightness Level = 77) *PLEASE NOTE that the A4 & A3+ SALE PAPERS are sold bulk-packed (without standard retail box).