Liquitex Ink is an ultra fluid acrylic made with lightfast artist quality pigments.  What you get is a pure permanent colour.  Pigments are processed the exact same way as they are for the Professional and Basics paints.  What that gives the artist is true colour purity and archival stability in an ultra fluid acrylic vehicle. Dries quickly and permanently, giving no chance of smudging or bleeding when rewetted or layered.  Pure liquid colour in a wide range of opacity.  Ink can be used on a variety of surfaces including canvas, paper, wood, plaster and fabric.  Pigment quality allows for artwork to have the greatest archival permanence possible lasting 50 plus years in gallery conditions with no colour shifting or fading while remaining vibrant and true. Exception to this would be the metallic colours as those pigments are naturally less lightfast. 
Techniques: watercolour, pouring, airbrushing, pen & ink, collage and mixed media
Character: ultra fluid, highly pigmented, dye free, non-fading, satin finish, permanent when dry.
For the ink comparison photo -  top one is a pigment based in and the bottom one is a dye based ink.  Right hand side of both samples was exposed to light for the equivalent of 50-100 years showing the difference between the pigment based ink and dye based one. 
As always, if you have any questions about this product or similar products don't hesitate to contact us at support@norcal-art.com!