Engraving is a true test of machine accuracy, repeatability, table flatness, etc. And even wood which has been planed flat directly on the machine can sometimes present problems when doing an engraving. (Because it IS, after all- WOOD!). Changes in wood grain density, knots, and direction changes of the grain around knots, etc. can create apparent cutting depth variations in an engraving. Particularly very delicate text engravings, with very fine lines, and small characters. What I have learned to do, through trial and error (a LOT of the error part!) is to start with a cutting depth which is VERY SHALLOW -maybe 0.003" deep. Engrave the first pass, and inspect the result. If not deep enough, I usually load the file into LazyCAM, and set the cutting depth a little deeper (maybe 0.002" at a time), and repost to Mach, and run a second pass. Inspect the results again, and repeat as needed. The wood grain density problems I mentioned above, can sometimes be overcome by using a little trick I have learned: with the file loaded into LazyCAM, select all characters EXCEPT the one (or more) character(s) that appear not to have engraved deep enough into the wood (due to a denser area of the wood grain) and DELETE them! Repost the file to Mach3, and run the program again. If they still don't appear cut deeply enough to match the other characters, you can always go back into LazyCAM and set the cutting depth a little deeper, and repeat until you achieve the best results. Using a V bit for engravings, to create a BOLD font, just select the desired characters to be cut as BOLD, and set the cutting depth a little deeper for these. You are still using the same font, but the results in the engraving make the characters appear as a BOLD font. Yeah, I know. It's a PITA process. But necessary sometimes to overcome the MANY variables which working with wood presents in order to achieve a quality engraving. It is a bit of an Art form, and learning to control the machine to become your "Artist's Brush" does invlove some rather tedious WORK! Starting with the "Fonts" I use, which are actually hand-drawn groups of lines, circles, and arcs which mimic actual fonts for the best engraving results. Hope this helps!