I want to put images in my overlay preset. 1st what type of files can go in it? 2nd. I want files to have NO background. I want to put logos in it but down want to see the white background of them, just the logo floating over the screen. I know in photoshop ou can do that, but im not sure what kind of file type you can save that in, and will ME read those file types? I also dont own Photoshop and have ZERO intention of buying it, anybody know a good free photo editor for mac or PC?