I can't tell you the brand for now. It's a french friend of mine who gave me a couple of sheets. I know it's decal paper dedicated to inkjet printers : I'll ask him what brand it is tonight.
THe printer is very important too, I believe; I made some tries with my old printer (epson, but I can't remember the reference) a few months ago, without any good result. Today everything worked great on first try with the HP printer. I don't know why
On the HP settings, I set up the paper type to "gloss paper". On other printers, I believe you should choose "photo paper", coated paper, or something like that.