Disperse dyes were developed in the 1920s to colour synthetic materials, some results can also be achieved onto natural fibres but the colour is always more subtle. Unlike other dyes, disperse dyes do not dissolve in water but the dye droplets are suspended in the solution and then penetrate the fibres when heated. When synthetic fabrics cool they trap the particles of dye within them and the colour is instantly fixed. The dyes can be painted onto paper and heat pressed onto fabrics to create colour and pattern. Pre-coated heat transfer papers are also available to purchase and use in the same way.