What are you using to make the prints? (Gimp, Photoshop, Etc.)
I think using a photo editor like Gimp , Photoshop, or Paint.net is the worst way to make faces, decal, prints, etc. I work with a vector editor called
Inkscape. It's free, open source, and works on all platforms.
Everything is an object that can be moved, resized, layered, recolored, etc, endlessly, without any loss in quality. If you look in the ZIP you DLed for these buttons, you'll find a SVG file that contains everything needed to make them. I did this so you can make your own buttons if you wish. When you think you're done, simply export to a PNG file, and try it out in Blockland.
If you're used to a photo editor, getting used to the concept behind vector art can take a little while. Ultimately it pays off in time saved and the quality of work you can put out.