They can be both. Number boards on the front tend to be decals. The rears are usually painted. I think the mudguards are mostly painted, but I've seen decals somewhere for them.
Personally, if you can afford it, I'd go for paint.
Yeh I would go for painted option, I have one of the thick stick on ones which has been good for stopping stone chips but now has started to come unstuck and it was a bit of a sod to get on .
Mood: My Jota goes rumpety rump! & I have my wife exactly where she wants me!
I`ve had both on mine and whilst the stick on type offer much more protection than a painted on board many people have problems with them staying stuck down. As for me, I had mine painted on and am very pleased with the end product.
I've had stick on (Pro Chip) number boards on 2 different bikes and been very pleased.
The trick is taking the time to put them on properly and carefully (or if you're cheeky get your dealer to fit them when in for a service and if it isn't on right, its their problem).
The stick on ones are a thick vinyl which stops stone chips.
Have a word with TecMoto - http://www.tecmoto.co.uk/ - as they're both a Ducati specialist and a paintshop too. They repainted my single seat with the numberboard and it's excellent.
Yes, I have an interest because they sponsor my race bike, but I wouldn't recommend them if they weren't worth it.
Speak to the owner, Chris, and tell him the DSC sent you. You might even get a discount...