Composition and Permanence:andnbsp;The colour index name is established and published by the American Association of Textile Chemists and Colourists and The Society of Dyers and Colourists. The colour index name is a generic category and does not refer to a specific pigment. While it enables the artist to form a general idea of opacity, transparency and lightfastness, for a pigment in a certain colour space, it does not provide definitive information. Many grades of pigment are available from a number of manufactures with a very wide range of physical attributes.

Chemical Name:andnbsp;The chemical name is a brief, commonly used generic type designation of the pigment types composition. in conjunction with the colour index name, the chemical name can be used to broaden the artists understanding of the source and nature of the pigment used.

Lightfast Ratingandnbsp;andndash; Permanence:andnbsp;The permanence of a colour is a measure of the lightfastness of the pigment when dispersed in a vehicle and subjected to conditions which emulate the exposure normally given a fine arts object. Such ratings are generally considered vehicle or media dependent and can vary between media andmdash; thus pigment which is suitably lightfast for oil colour, might not be lightfast in watercolour. Our ratings utilize a combination of historical data, accelerated testing and data from pigment manufacturers to establish one of the toughest standards among artistsandrsquo; colour makers today.

Opacity Rating - Transparency and Opacity:andnbsp;Each of our colours has been provided a designation indicating relative degrees of transparency to opacity. Please consider these as a guideline because any thin film application, while not necessarily transparent, can be interpreted by the view as such.