User blog comment:LumpZ/My "Sketchbook" of sprites/@comment-4511886-20120302151745/@comment-4530673-20120303034612

Yeah, mspaint. To open the terraria files, you have to find a program to convert the files into PNG folders. You can't make the invisible effect on PNG files with Paint. You have to use another program to make it invisible, though I just leave it as-is.