Arches Aquarelle watercolor paper is acid-free and chlorine free, made of 100% cotton fibers which provide strength and stability. The paper is tub-sized in natural gelatine and air-dried, it can take scrubbing, scratching and erasing while keeping the original intensity of the watercolor. Arches Aquarelle uses no optical brighteners so it's natural white color will not yellow with age and archival value is ensured. Arches Aquarelle is excellent for watercolor, gouache, pen and ink, acrylics and calligraphy.