Blankets are available in two grades. A pressed wool using high quality wool and the professional quality woven wool blanket. The woven blanket is perfect for producing dense blacks and fine aquatints and will last for years if well looked after. It is suggested that both blankets be hand washed gently using wool wash and warm water. Generally at least two blankets are used in printing and sometimes as many as four. The number and thicknesses will be determined by the plate. A general rule is the finer the plate the finer the blanket and the more deeply bitten the plate then the thicker the blankets. The heaviest blanket should be placed closest to the roller with the finer blanket closer to the paper.