1. First, open up the folder of the Chimera theme that you're currently using. If you haven't yet installed a custom bootloader theme, then your theme folder will be the "Default" folder under /Extra/Themes in your main hard drive.
First, open any icon with Preview.
LoginToLion bootloader theme). This is the icon that is displayed for all of my Mac OS X hard drives on the bootscreen.
3. Under "Tools" in the menu bar of Preview, click "Adjust Size". Change the following parameters:
- Change "pixels" to "percent"
- Uncheck "Scale proportionally"
- Change "Width" to 80
You don't need to adjust any icons that you see on your bootscreen; for example, if you don't have any Linux hard drives, don't bother adjusting any of the icons for Linux (called "device_ext3.png")
NOTE: Do not adjust the images "font_console.png" and "font_small.png". These are the images for the text on the bootscreen; if you adjust them, Chimera/Chameleon won't be able to read the text correctly.
And that's all there is to it! Chimera will still stretch out of your icons, but now that you've unstretched the icons beforehand, they'll look completely normally when on the bootscreen.