Using only DecoArt Pouring Medium, did the first one. For the the second one, added 4 drops of silicone to some of the white. So more cells. Talk about the impact of surface tension, like when you have a greasy sink of dirty water when doing dishes, and you add a drop of dish soap. That is breaking the surface tension. That’s what an additive can do. Do you have to have it? No. Absolutely not. If you want cells, it makes cell creation a lot easier.