I've had a few questions on the coloring technique using Gamsol and Prisma colored pencils. The main question I had was where to find Gamsol. Basically Gamsol is an odorless mineral spirit (OMS). You can find OMS at your fine arts supply store. I've been told that you can also find it at Home Depot too. Either way I can't find it here in Barrow so I ordered if off the internet through a fine arts supply site. I am including a photo of my Gamsol stash with blending tools. I hope this information is a help to you.