Cartridge paper is a must in any studio space or art supplies store, it is available in a range of sizes, packs and weights including the popular A4 110gsm that is available per sheet, 20 pack and ream. Cartridge Paper is a white drawing paper that will withhold charcoal, graphite, pencil and paint. It is a very universal drawing paper that is used by kids, intermediate to professional artists and many crafters. Paper cartridge has a fairly smooth surface and can be used for a multitude of art and craft projects.