by the canning suppliers. I have always been told that the canning caps cannot be reused, and I had to ask myself, Why not? When you remove the cap from a sealed jar, half of the seal isn't left on the jar. So, in the process of making a couple of jars of jam, I decided to do an experiment, and canned up three jars of water, using old lids, just to see if they would seal. !00% success, so far. I have marked those particular lids and am going to continue to use those same lids, until they quit sealing. When you think about it, the consistency of the seal is not changed, with use. When you throw it into a pot of hot water, it softens up, just like a new lid. Quit wasting your money.