I was wondering if there is a way to add finishing detail on top of dried oil paint with colored pencils. The main problem is that the pencils remove paint and under layers with the sharp point. Especially dried thin glazed layers.They get chipped easily. I tried to seal the paint with retouch varnish, but the varnish is to slick and has no tooth when I try to work on top of it. Any suggestions or techniques that you might know of that can allow me to work in the Struzan-esqe way except in oils without causing chipping?