Superior pigments of unsurpassed light fastness intense colour ideal for detailed and wide area work polychromos artists pastel crayons can be ground into a fine pigment powder using sandpaper and then mixed with oil resin or an acrylic medium to form paint drawings made with polychromos pastels can be wiped or treated with a paintbrush dipped in liquid paraffin to give fine colour transitions rectangular shape of the pastel allows several different line widths to be acheived by using