Anodised aluminium: settings that actually give crisp white marks

Sana Qureshi11 August 2026 3 replies 1232 views

Sharing what worked after a lot of scrap. This is on black anodised aluminium business-card blanks, LP4 diode module.

Mode: engrave, greyscale off, 1-bit line art
Power: 100%
Speed: 1200 mm/min
Passes: 1
DPI / line interval: 1000 DPI (0.025mm)
Air assist: on, low

Key things I got wrong at first:

Too many passes. A second pass on anodising doesn't go whiter, it goes grey and fuzzy because you're now hitting bare aluminium. One clean pass is the target.
Focus matters more than power here. 0.5mm out and the edges bloom.
Wipe with IPA before and after. Fingerprints show up as blotchy marks.

For photos on the same blanks I drop to 900mm/min at 100% with Jarvis dithering and it holds mid-tones surprisingly well. Anyone got a better dither for faces?

#anodised #aluminium #lp4 #settings

3 replies

Tomasz KleinLP52 weeks ago

For faces I use Stucki rather than Jarvis — slightly softer transitions and less of the worm pattern in the shadows. Also try lifting the black point in your image editor before you export; anodising has almost no dynamic range at the dark end so you're better off compressing tones yourself rather than letting the dither guess.

Sana QureshiLP42 weeks ago

Stucki is better, you're right. Also learned this week that "anodised" from one supplier isn't the same thickness as another — same file, same settings, noticeably different white.

Beth CarrowLP42 weeks ago

Saved. I do a lot of pet tags on these and have been running two passes like an idiot. Trying single pass tonight.