"I bought four of these for my daughter for all her Friends sets (She has 59!). But she no sooner took them out of the package and they began to warp and curl up. They will not lay flat unless she builds a rather heavy element on them. I've designed a couple architectural models, but I'm afraid to buy this baseplate for fear it will do the same, even though it is the size I need. Hey Lego, for the price, how about making the plates heavier? Legos aren't just for kids anymore, and I'd like to get my money's worth. Thanks!"