I've been using the same cookie sheets since 1968 and they are good, heavy-duty ones. However, by now, they've gotten pretty scratched and beaten up. They were originally Teflon-coated but, as you might guess, after over 40 years of constant use, the Teflon is long gone.
The structure of the cookie sheets was still sound and I really didn't want to discard them and buy something newer, probably more expensive and of poorer quality. So...what did I do?
I did some homework and bought several packages of Teflon pan liners
. They're fantastic. I cut some to fit my round cake pans, others to fit my cookie sheets, still a few more for my oblong baking pans, etc.
I've had them for over 10 years and couldn't be more pleased. Most of the time I hand wash them but, on occasion, I've put them in the dishwasher.
Just another thing for you to consider.