Sail numbers & class insignias: how do you get them off sailcloth?

[Greenheart]

This is an idle question that's been idling around my idle mind for a couple of idle decades, but never really justified asking...

Most dinghy-mainsails have the hull's number printed on them. I suppose it's handy for identifying the boat in a fleet.

But if you never race, and aren't interested in advertising the type of boat you sail, or would just like to see an unadulterated triangular expanse of cloth rising overhead...

...is there a technique for getting sail numbers and insignias off, without damaging the sail itself?

 

[yoda]

Most will peel off after gentle application of the wife's hair dryer.

Yoda

 

[Seajet]

The numbers and insignia may come off, but the U/V or adhesive shadow is likely to be there forever.

I'd only do it if changing numbers on a secondhand sail, otherwise I think it looks worse than the wrong info !