So i bought a new pickguard for my guitar. My old pickguard had alluminum on the back of it, and this one didnt. I wanted it to be the same, so i put aluminum on the back with spray glue and cut it out with a sharp knife. Not a bad job if i do say so myself! But now a problem...The knife wasnt thin enough. So when i mount the pickguard on the guitar, i will be able to see the aluminum. Its sticking out ever so slightly from all the sides. Should i go around the back of the pickguard from the edge all the way around a little or what?