Windsor & Newton Artists Acrylic Slow Drying MediumThe jury is still out on this stuff. I tried it for the first time today on an art journal page and I'm not entirely satisfied with the results. It certainly made the acrylic paint much more blendable and slow drying but I found it rather gloopy. With certain colours my brush seemed to actually take the paint away rather than lay it down and I had to rework and rework certain areas. I'm not giving up on it just yet I may have added too much though it says 1:1 and that doubles drying time. I may try just a tiny amount next time and will update on here my findings.