Gamblin - Galkyd G-Gel - 150ml - Gamblin Galkyd G-Gel is a gelled alkyd resin painting medium, which Robert formulated for painters who want to create transparent impasto. Thixotropic G-Gel holds marks and brush strokes. G-Gel makes impasto of approximately 1/4" thick. You can apply multiple layers. G-Gel does not contain driers so it does not dry as fast as most gel mediums. Adding driers causes oil paintings to darken and become brittle over time. G-Gel contains a very small amount of silica so it is very transparent and lightweight.