Light touch vs. poking holes in foil [Edited]

Two extremes of operation here. One digging in the probe hard enough to tear up a strip of 25μm foil and lift it up off the bed:

Completely accidental, but may be interesting to carve up foil at some point and make circuits? Next one is more interesting technically.

At 3mm/s I redid the 400μm logo with the probe, within errors, 5μm higher than the last etching. Here it barely skims the marker dye layer and is quite hard to see, requiring more creative lighting. Looking at the corners on the μ (if you can make it out) you can see that they are substantially better defined than previous efforts. So, stay slow and don't tunnel the probe into the ground.

Another thing that came out of this: I don't like the look of the curves either side of the point of the teardrop. They should be straight on the diagonal. The straight bits on the μare straight. What's up? Perhaps the GRBL software is doing clever things and has an "allowable margin of error" setting somewhere that becomes more apparent at micron-level movement. Further investigation ongoing...

[EDIT]

$11=0.010 (Junction deviation, millimeters)
$12=0.002 (Arc tolerance, millimeters)

Hmm, that might do it. Let's make that a wee bit finer. Ah, GRBL only takes it down to 0.001mm - fair enough, it'll do for testing. I get to a micron where it matters and I'll be happy.