Procion mx dye colours black cold water dyes which can be used to dye vegetable fibres such as cotton linen sisal and for batik techniques they can also be used to dye silk and wool to a lesser extentprocion dyes produce bright clear colours and can be mixed in any proportion and strength to produce many colours make up small quantities as required and use within 10 days excess quantities will store for up to 3 months in the freezer500g