I've wrapped a set of tubes with square cut outs. Turned out to be a PITA, so I made a template on my graphics program so my machine can cut out the graphic wrap. The tubes are small, so you wouldn't need to wet the surface. Just lay the vinyl on the front first, and use your fingers to rub the vinyl on the tubes. Take your time and you won't have any air bubbles. It's a pain to do, but it looks good when it's done. I've attached a pic of a ski I recently did for a client. Wrapped his RRP with black vinyl.