Have you ever tried using Parafilm? Have you even heard of it before? It is one of the best masking material I have ever used. It stick but is not sticky so it doesn't leave a residue. It is very thin and you can see what you are masking under the film. You can even mask over Metalizer paints and not pull the paint up.
You cut a piece off the roll and stretch it to about 4 times its original size and just start masking. Masking curves are no problem because of its thin properties. You can roll up the mask with your finger. If you need to push the mask edges around just get a toothpick (or I like to use a wet toothpick) and push the Parafilm into place.
Its original use was to cover medical containers but it has found an equal use in modeling. I believe the 'sticky' in Parafilm is simple wax.
Since I started using Parafilm I ACTUALLY LIKE masking!
![Shock [:O]](/FSM/CS/emoticons/icon_smile_shock.gif)
Here is a great web site that describes very well how to use Parafilm in modeling:
http://www.clubhyper.com/reference/usingparafilmda_1.htm