To scan regular printable pages.

No point in saving B&W to Jpeg format.  Try Png.

With Kooka.

    Scan size:  Custom
    Preview, then select an area of approximately this size:
      200mm x 260mm  (Could be fine-tuned a little better)
      (Varies a lot but makes a PNG in the 50k range)
    (I think you must re-preview after every preview scan.  It doesn't
    seem to use the "Selection" setting shown unless you do.)


    Resolution: 140  (It seems that this effects clarity, not image size)
    Scan mode: Lineart
    Output file format: PNG