Xyron Pro Two-Sided Standard Use Laminate Refill Cartridge (DL1251-150)

Do I have to laminate both sides or can I just laminate the top?

How clear is the laminate? If I put a glossy printed photo through will it look perfectly clear or kinda foggy?

I can't seem to find the refill roll that would be laminate on one side, and permanent sticker (not repositionable) on the other. Can you help?

will it fit the 1250 machine?