Jackson's Black Straw Hat Varnish is a quick drying shellac based varnish with added dye making it easy to see where it has been applied.
Commonly used for backing etching plates due to the fact that it is soluble in methylated spirit: it will not be affected when working with traditional grounds and white spirit based stop out varnishes on the front of the plate. It works very well with sugar lift technique. For added acid resistance we recommend applying two coats of varnish.