We order our rolls on paper/film/canvas/silk at two compagnies: the Chinese & Papergraphics.
Go to stichting>communicatie>graphic design here you find a list of materials and prices. Prices of papergraphics are excl. taxes. In the graphic storage (no. 12), you can find sample books of both companies so you can feel/smell/ see what the material and quality of the prints look like.