Truly we wanna say these food storage containers are well-built. By constructing from real food-grade plastic, so they are of smooth feeling indeed. And maybe when you received these containers, they are stacked together tightly, or even more tighter so that you have some difficulties in pulling them out of another. Then please take it easy since that here has the tips on it: First, you are supposed to grasp both sides of the containers(longer sides). Second, properly pressing some bit of strength to them. In this way, they can be separated easily.