Sealing in an autograph done in sharpie
 

If one were making a guitar and the customer wanted to get an autograph which was done in sharpie sealed in, what would be the best way to make sure the autograph didn’t bleed or run. To my knowledge nitro or shellac will dissolve the sharpie.

Any ideas?

Use an acrylic based paint, sand all areas not signed to help key the coat in

http://www.mirwa.com.au/images/IMG_3076.JPG

Nitro lightly misted on in a few coats has worked for me.

Like Okotok, spray light coats with Nitrocellulose. Of course, that's if you don't care about the value of the instrument. ��

I too have used nitro without any problems. Don't touch it with shellac though.