Little Birdie's easy One Step Crackle Medium is great for creating a wonderful antique look of aged paint. The easy-to-use Crackle Medium can be used on various surfaces like wood, paper, canvas, glass, metal, terracotta and more. This water based crackle medium works well with chalk paints, acrylic paints and similar mediums. It is non-toxic and dries clear. You can try it out on wooden furniture, decorative wooden alterable, pieces of wall art or other projects. Imported.