GOLDEN OPEN Acrylics are a slow-drying formulation with a slightly softer consistency than GOLDEN Heavy Body paints. The increased working time of these colours expands their range to include more traditional techniques once only possible with oils. Because OPEN Acrylics dry slowly, painters who cover their palettes or use sealed containers have been able to use the same colours for weeks, reducing the amount of paint wasted and preserving colour mixtures for future use.

The Lightfastness Ratings are provided by the American Society for Testing and Materials (ASTM) in the standard for "Artists Acrylic Emulsion Paints". (ASTM D 5098, Annual Book of Standards, Volume 6.02).

Colours with a Lightfastness Rating of “I” are considered Excellent ("Exc.") and those with a Lightfastness Rating of “II” are Very Good ("V.G."). Where Lightfastness Ratings have not been obtained according to ASTM test protocol, "NA" is indicated in the table. In these cases, data from pigment manufacturers and our own test facilities have been used and an appropriate description assigned under Permanency.

Opacity/Transparency, we have determined that an eight-point scale is most appropriate for describing opaque) to 8 (most transparent) to indicate the relative opacity/transparency of that colour.

The C.I. (Colour Index) Name is an internationally recognized code assigned to a particular "colorant." The C.I. Name consists of the category (type of dye or pigment), general hue and serial number assigned, based on its chemical constitution. For example, PB 60, Anthraquinone Blue, indicates a specific Pigment Blue. The C.I. Number is a five-digit reference number assigned in the Colour Index based on the chemical structure of a colorant, regardless of usage class.

†NOTE: The Golden C.P. designation indicates concentrated cadmium pigments (CC).