Description The Platinum 3776 Celluloid fountain pen in Koi features a celluloid in a beautiful blend of vibrant pinks, reds, and glowing cream white, reflects the traditional Japanese art of raising Koi fish. , accented by gold-plated trim. The Platinum 3776 Celluloid fountain pen in Koi uses a 14k gold nib that is available in several nib sizes and the pen fills via the included proprietary Platinum converter for use with bottled ink, or with Platinum cartridges as well.Celluloid is a traditional material for pen making, one that offers unparalleled depth, feel, and color. Celluloid is a very difficult material to use, requiring an exacting process to create, followed by an extended curing process to ensure the stability of the material. The Platinum celluloid is prepared to exacting specifications and carefully cured to ensure a perfect material for the pens.