Thanks, it is all helpful.
The last time i resesrched a bit, I saw people complaining that some trays listed as stainless steel aren't actually 100 percent steel.
Its quite a rsbbit hole!
I seem to remember roast potatoes leaving the crispy outer part stuck to the tray, and being left with the soft "inner", so thats why I've always gone for non stick.
That, and the fact that i can get a non stick tray in poundland!!.
Mine do look pretty disgusting, though. 
"Old fashioned" expressions that young people have never heard.


