I have a metal allergy so metal thimbles are always a problem.
I've tried the leather thimbles and they are OK but for some reason, they make my finger sweat. Don't laugh, but I tried one
of those gummy thimbles. They look like a molded gummy bear.
They are comfortable, light and they work great. I got mine at my LQS. I liked it so much I now have a red one and a blue one.
Good luck, M.E.