I had been using some cheaper silicone mats for baking cookies and they actually get bigger and warped while in the oven. Sometimes my cookies would be odd shapes because the silicone mat had shifted and expanded in the heat of the oven. Not with these little mats!! I bought these and they fit my pans better than the other cheaper mats I had used and they do not change shape or size while baking. They are absolutely worth getting! I don't know why I put up with the other ones as long as I did. These are fantastic mats for the price. Buy them!