You are not wrong there Zig, beautiful work indeed, my congratulations Arbo.
For others that follow…
The free software ‘Mach1filter.exe’ (available somewhere here – if not then contact me) makes a pretty good job with creating the toolpath for rotary (spindle) machining of Lithophanes. (As with most image work the original image has to contain good contrast etc. and some practice will be necessary to achieve the best results).
Also the free software ‘Mach3 Impact / Laser Engraving plugin’ will enable Lithophanes to be laser cut.
http://www.machsupport.com/forum/index.php/topic,12444.msg164439.html#msg164439Tweakie.