These are FANTASTIC !! Nothing sticks to them. They can be used alone or in a baking pan as I use them most. They make cleaning up so easy. Use them grilling as well. I first bought some several years ago and used them several times a week and after about 3 or 4 years they started turning dark so I bought new ones but the older ones still worked I just didn't like the darkening of them. I also cut on them and put grooves into them so I don't recommend cutting on them. Speaking of cutting you can custom fit them to any pan by cutting them obviously. ???? Since I have different size cookie sheets I cut some to fit and leave others for baking alone without a pan. They are a great value considering how long they last and making clean up a cinch so that alone is worth it to me. They are a must have for anyone especially that avid baker out there. I highly recommend these and a perfect gift idea also so order several boxes for that holiday baking you'll be glad you did. They come 5 per box.