Watercolour paper blocks are glued on all four sides, eliminating the need to wet and stretch the paper before painting, as the glue prevents the sheet from curling and buckling during painting. Once a piece is finished, simply slip a blunt knife or letter opener under the top sheet (an unglued section in the middle of the top edge) to lift it up and reveal a brand-new sheet beneath. They are excellent for all types of watercolour painting and ink drawing and the ideal portable painting surface for outdoor painting. Each block contains 20 sheets of 300gsm acid free, 100% cotton paper and is available in smooth, medium and rough surface textures. It is sized with natural gelatine and is a natural white with no optical bleaches used during manufacture. They are available in convenient sizes 125x180mm, 180x260mm, 230x310mm, 260x360mm, 310x410mm, 360x510mm and 460x610mm.