I suspect the program is simplistic enough that it fails to allow for mapping the tat onto a non-flat surface...which would account for how funky the results are. Not that the tat displayed on the Palm looks like a real "work of art".
Testing with a felt-tip pen might be a good start. :-)
I just can't not think about the Harrow from
Kafka's <i>In The Penal Colony</i> reading about this machine, though.