What an awesome idea! I never figured doing that....CD pens are alright though?? Like they don't w]come off? My 3DS is a pink one and it has a lot of wear and tear (love marks as i call it) from rubbing in my hand bag when I go out XD; so yeah been thinking about doing some thing but...not sure, what...but now you gave me an idea C;
I love the shading and such nice shading too! Great stuff!