This range of blocks each contains 15 sheets of Winsor & Newton Artists Water Colour Paper. They are gummed on all 4 edges to reduce the need for stretching. This range is available in 140lb/300gsm weight with Hot Pressed, Cold Pressed/NOT and Rough surfaces. Artists Water Colour Paper has been developed for artists seeking the finest in water colour paper. Made on a cylinder mould from 100% cotton, Artists Water Colour paper is an extremely strong and stable paper and is guaranteed 100% acid free for archival permanence. It is internally and externally sized and has a clean white surface which helps maintain the brilliance and transparency of the colours applied