I bought the circle cutters and I use them all the time. There are several things about them that I really appreciate. First, they are very sturdy and make very clean cuts. Secondly, and probably the best part, the cutting edge is sharp and consistent all the way around the edge. It's not sharp enough to cut your fingers or anything, what I mean is you don't get that little rough spot in your cut clay like you get with most metal cutters because the edge on these cutters isn't spliced together. These circle cutters are so durable and easy to clean they will probably last a life time. I think I'll get the heart shaped ones next, as these are worth having in my cutter collection. Also, I took the two biggest cutters in this set and put them in my kitchen, I don't use them with polymer clay. I use them for cutting biscuits and cookies, they work great there, too!!