Tkinter 8.5 reference: a GUI for Python

For bitmap options in widgets, these bitmaps are guaranteed to be available:

The graphic above shows Button widgets bearing the standard bitmaps. From left to right, they are 'error', 'gray75', 'gray50', 'gray25', 'gray12', 'hourglass', 'info', 'questhead', 'question', and 'warning'.

You can use your own bitmaps. Any file in .xbm (X bit map) format will work. In place of a standard bitmap name, use the string '@' followed by the pathname of the .xbm file.