I put the merest scratch on my new Remington R1 when I last installed the slide stop. It's barely visible with the pin installed, but I was really annoyed with myself for doing it.
I have the classic "idiot scratch"/"new guy to 1911s scratch"/"human-induced-semi-circular-slide stop-on-frame-contact-artifact" on my Series '70 Gold Cup from way back. It was my first 1911 and I was used to my 9mm Hi-Powers, with which I never had the problem.
Cruising the 1911 forums, I see that it is still an issue for many 1911 owners. Someone is marketing a plastic gadget called the "Idiot Scratch Protection Tool" or ISPT. Check out ISPT.com for details.
Other methods are to use a piece of masking tape or business card, but I caught a bit of material under the slide stop doing that.
It took me ten minutes to cut out a couple of ISPTs from a plastic coffee can lid - one for my stock R1 and another for my Gold Cup with large mag release button.
I think that the real idiot would be the guy who would buy the ISPT and pay S&H costs for a piece of plastic.