I have wanted covers like these for years so I could put left overs on a plate, warm in the microwave, and eat all on the same dish. These actually do seal right on the plate and keep the food fresh for a couple of days until you can get it used. My dishes are smooth and the instructions that came with indicated they might not seal if you had a design in your plate. It is so nice to be able just to pop these over a dish – no plastic wrap to wrestle with, no thought you had it down tight and now it all dried out. They wash and clean up well – are easy care. Also nice if you happen to just sit down to eat and get interrupted to take care of something. I put it on my plate and it keeps my food warm a few extra minutes so I don’t have to come back to a cold dinner. Someone was doing some good thinking when they designed and made this product.