Hi @Paul
With this method of carving 2.5D the machine will still do a watering style cut and the z-axis will step down for each level. If you have enough steps to the grey scale then it can get pretty smooth…
See some examples here:
https://discuss.inventables.com/t/tip-jar-bounty-500-claimed-by-sketch42-iphone-6-case/9122/14
And here:
New to CNC Machining - #23 by sketch42