Arches Watercolour Blocks 20 sheets 300gsm | Various Sizes/FinishesMade the traditional way, on a cylinder mould, this paper has a harmonious natural grain. Thanks to this method, the fibres are evenly distributed, the paper slackens uniformly when wet.Its composition with long fibres of 100% cotton gives the paper its strength, beauty, a natural, lasting whiteness and an inimitable touch.ARCHES is the only paper mill in the world to gelatin size its watercolour paper to the core. This preserves the lustre and transparency of the colours whilst preventing paints from penetrating the paper. It allows superposing of washes and gives it added strength to resist erasing and scratching without tearing or linting. It also allows paints to be removed, either wet or dry, easily revealing the whiteness of the paper. ARCHES Watercolour paper can absorb a large amount of water with limited deformation.