- Open a favorite image that you like to turn into a favicon to appear in your browser's location bar
- Click Image->Mode->RGB
- Using the erase tool, erase any areas of the graphic that you'd like to be transparent
- Using Image->Scale, resize the image to 32x32, the proper size for a favicon
- First save the file as a GIF
- Select * Convert to Indexed using default settings
- Click Export
- Save a copy as .ico.
- It will give you a number of choices for bits/pixel:
1 bpp, 1 bit alpha, 2-slot palette
4 bpp, 1 bit alpha, 16-slot palette
8 bpp, 1 bit alpha, 256-slot palette
32 bpp, 8 bit alpha, no palette