Printfox (or Printfox/Pagefox) bitmap is a raster graphics format associated with the Printfox and Pagefox desktop publishing programs for the Commodore 64. Most of the information about it is in German.
There are at least 3 formats of Printfox/Pagefox images. All are RLE-encoded:
.BG with resolution 640x400, the first byte is 'G' (0x47)
.BS with resolution 320x200, the first byte is 'B' (0x42)
.PG with resolution 8x8 up to 640x800, the first byte is 'P' (0x50)