I would recommend buying LOTS of these doming blocks. They of course are easy to clean cured resin off of, so as long as you don't use an actual flame or a lot of heat on them, they should last a long time. Tony always makes high quality products. I say I recommend buying a bunch because even for a keychain I use at least 2 (just my preference), and I make lots of little pieces. This is solely my experience, but I really like using these over traditional doming mats for small to medium projects.