Sooo I thought I’d buy other containers to house my DIY slimes which runneth over. I purchased 13 oz glass containers. The slime sticks like glue. Horrible to get off. Then I bought 13 oz plastic containers. They stick like glue as well. The extra containers CWS sell are made of plastic that slime miraculously doesn’t stick to. Go figure! In the process, I lost 2 oz of my birthday cake slime and that makes me very sad. Anyway, my tip is to ‘stick’ with the containers CWS sells. They are the only ones I’ve found to actually work well with storing your slime properly.