Strong 40 pound stock paper, no inks, and no dyes! Paper, the material aviculturists recommend. * Clean your cage in seconds, no messy clean up or sifting through cat litter type products. * Absorbs moisture quickly so your birds do not have to be exposed to dampness and possible contamination. * Custom safe cage liners that are efficient and sanitary and make inspecting bird droppings easy. * Give your bird the best liner available for a happy and healthy pet.