that is iffy. when your edges hit the topsheets, if even a little of the paper is exposed, water will soak into it. It will also be a lot heavier, where painting them really does almost nothing.
However, You can use pencil to pencil down the design before you sharpie it. you can erase pencil off of the flat white too. Just be gentle. Also, get the really skinny sharpies, and only use a second color of spraypaint if you have to, other colors dont flex with your ski like white does, and isn't as durable.