I think if you paint or put stickers on a helmet it invalidates the CE homologation. So perhaps not a good idea for your bike lid. Fine for M3W where its not compulsory wear & is more for looks & weather protection.
Actually race car drivers have their helmets painted all the time, and I see stickers a lot. I don't think it influences the safety qualification, but then I am in the US, so it might be differnet eleswhere.
Right about the paint Tim, you can not use acrilic paint for example, it penetrates the Helmet and abuses the Fiberglas shell. The trick is to use Lexan paint which is used for RC-cars...that paint is not penetrating the underneat laquer either Fiberglas. it just stick on and admits to do some vintage scratchings in the painted object
Cheers, Georges
M3W, Super Dry edition, sep. 2013 ...called 'DogNose'
