bootskins

Any Graphics program will do. Here's a tutorial for Photoshop.

Bootskin Tut

Like KiloKrash said, any graphics program work to make a boot wallpaper

It's a good idea to have the program Bootskin to see if everything works right

Well that does seem like common sense, otherwise why make a bootskin if you don't even have the program in the first place to test and use it on?

Sounds like common sense. However, you'd be surprised at the number of bootskins rejected because they don't work (and can never have worked)   

When I make a bootscreen, I made it with BootSkinBuddy (Site of Desktopgadgets). Afterwards I see the bootskin with the program of Stardock called Bootskin to check if everything is allright. There are many programs to edit a bootscreen. You have BootskinBuddy, BootXP, Bootskin,etc... But the common part, I think, it that they all use the Bootskin of Stardock together with their other Stardock Software

See it like a graphic program. The one likes Paint, the other one Photoshop, another one PhotoImpact and so on.. Every person uses his own program, but to share the picture or skin, you have to test it also with the program all the rest is using, to see if there are errors or anything that makes the skin not useable for others. If you understands me..  

Yes that true. You use youw own program to create the skin, but you have to test it with the program everybody uses, here in this example bootskin of Stardock.