Arches Watercolour Pad Medium 185GSM - A4Professional grade acid-free watercolour paper of the highest qualtiy. 100&#37 cotton, cylinder mould made with natural gelatine sizing. Natural white (no optical bleaches).The choice of leading watercolorists all over the world Arches is the product of five centuries of papermaking experience. Arches watercolor papers are mouldmade in France with 100&#37 cotton fiber content. They are pH neutral gelatin-sized and air-dried. You can always rely on Arches to be consistent.