Actually, I started saving them as .png halfway through this set when I noticed that the text looked horrible if I saved Engineer as a .jpg. All of the themes icons except the first one are .png while the rest are .jpg (order of making = Artist's choice, Category, Themes - I actually think Spock may have been made last).

I think I've discovered the brightness/contrast tool as I worked on this set of Sailor Moon icons that I've just posted. Some of those icons I feel bleh on, but I'm pleased with several of them. I haven't started to work with the sharpen or blur stuff because...I dunno, I think I'm just kinda playing around at the moment trying to understand how to make things work.

Thanks for the compliments though - a lot of people seem to like Spock! And I'm a beginner in the sense that I'm starting to go beyond just cropping, putting a one pixel border around the icon and maybe slapping on text as well as sharing the icons I make with others instead of just making them for personal use.