These are the beautiful Nakaya Celluloid fountain pens. There are currently three colors available: Goldfish, Tortoiseshell, and Jade. Celluloid is a flammable, half transparent plastic material which is made by mixing nitric-cellulose (sulfuric acid and nitric acid are added to cellulose), camphor and alcohol. When colored it achieves a splendid result. most pen barrels were made of this material in the past as it is easy to cast and carve and also produce in a variety of colors and patterns. However, as it must be dried more than 6 months to prevent from deforming and twisting it has been recognized as a difficult material.