Art Spectrum Liquid Spectrum Inks are brilliant, water-resistant, non-toxic, lightfast ASTM 1 & 2 colours that have twice the pigment concentration of standard ink ranges. The colour strength allows them to be diluted to Watercolour like washes or used undiluted to make bold, vibrant artworks. When intermixed and used in conjunction with Art Spectrum Liquid Spectrum Metallics this range creates an unlimited vibrant palette for the artist. Blue Wool Scale ratings of 6,7,& 8 are considered permanent for artistic purposes. Always shake well before use. Art Spectrum Liquid Spectrum Inks (acrylic based) are clean, bright, strong, intense colours that mix into clear epoxy resin extremely well. The acrylic inks are fast drying, water resistant when dry and have an exceptionally smooth flow.