Using PaintBrush, Dots stroke, Basic material, Z intensity 1, RGB intensity 100, MRGBZ all on
Alpha was Brush22, the lightning/veiny brush, rotated 90 for about half of the strokes – holding the Alt key let me stamp in some cracks (it reverses ZAdd into ZSub)
Didn’t have my tablet plugged in, but a fixed brush size might work better anyway for uniformity of the effect
Could be used to prepare a “canvas” before painting, or with just ZAdd/Zsub after painting to add the effect
Pull + push + Alpha + Brush = painting 
Have good research !
Pilou
Interesting experiment - worked pretty well, I’d say. 
thanks, guys!
it wouldn’t be too hard to make other brushes for the purpose of prepping a “canvas” with other textures that have depth, e.g. woven canvas, pebbly board, watercolor paper – which maybe could be used with a brush set to paint at a fixed Zdepth in the Picker (or not)
I tried an earlier experiment with a material for watercolor paper that used noise + colorbump, but the trouble was that even with ZAdd off, the paintstrokes were also colorbumped, giving them a defined edge