...and
I always define Z=0 at Top, Middle and always make sure I fib "just a little" about the model's XY dimensions when importing it, telling MC it's just a wee bit larger (like 0.05") than my blank.
I've discovered that "stock" lumber isn't and that using the center and cutting just a little oversize (sort've) (often) guarantees decent results with "nearly right" sized blanks.
Also, I don't bother defining the model dimensions, just letting them default to those of the digital model that was input. If I have a bw image to input, "black" (assuming I choose "black is deeper") will be at the Z dimension I told MC when I input it--and note that it can be anything I want--and white will be the top.
Imagine I have an image of 50% gray letters on a black (100% gray) background surrounded by a white border. If I import the image to MC and say that it's 3/8" tall, the deepest cut (to black) will be 3/8" deep and the letters will be 3/16" tall. If 1/2", make those numbers 1/2" and 1/4" respectively. (So that you don't have abrupt up- and down-cuts at the black-white borders, bring the image into GIMP first and blur that region first. Do the same with gray-black too, but less strongly.)
I just ran across an Etsy store that does beautiful multi-layer signs for family names, and stains the letters on each layer differently. Quite striking.
https://www.etsy.com/shop/Lovejoystore? ... -info-name

- LovejoyStoreSign.jpg (19.44 KiB) Viewed 6393 times
Gimpchat.com has a tutorial for adding a picture frame to a photo: the same technique can be used in GIMP to add an undulating grayscale frame border to the image before being brought into MeshCAM. (User ofnuts created the
sine qua non script; user mahvin wrote the tutorial.)
http://gimpchat.com/viewtopic.php?f=23&t=1119--
David
P.S. I have no affiliation with lovejoystore in Minnesota.
I am not Dan & Kathy BRADY either.