OPEN Acrylics are a slow-drying paint with a slightly softer consistency than our Heavy Body paints. The increased working time of these colors expands their range to include more traditional techniques once only possible with oils. Thick applications can dry extremely slowly, so we recommend artists only use OPEN Colors thinly (< 1 mm). Drying time can also be accelerated by mixing OPEN with faster-drying acrylics like our Fluid and Heavy Body colors. The slow-drying capability of OPEN Acrylics also makes the suitable for some printmaking techniques. Because of the slow drying nature of these paints, it is recommended that work be left to dry for a minimum of 30 days before varnishing. During this period, it is also important to keep the artwork in a dust free environment, as the tacky phase of drying can cause small particles to become stuck and sometimes trapped. (2 fl. oz. tubes)