Laser materials · Anodized aluminum

Laser engraving anodized aluminum

Anodized aluminum is the easiest way into metal engraving. A diode, CO₂ or fiber laser removes the coloured anodized layer and leaves a crisp, bright mark, with no marking spray needed.

How it works

Anodizing grows a thin oxide layer on aluminum, and the colour comes from dye absorbed into that layer. The laser removes or bleaches the dyed layer, exposing the bright metal underneath. You are not cutting or deeply engraving the metal; you are taking off a coating a few microns thick. That is why it needs so little power and why almost any laser can do it.

What to make

• Metal business cards
• Pet ID tags and dog tags
• Tool and equipment labels, asset tags and serial plates
• Keychains, phone cases and flasks
• Control panel labels and enclosure fronts

Numbered runs of tags and labels are quicker with the Tags & Marking studio in the app, which makes sequences of valve, cable and asset tags in one file.

Getting a clean, white mark

• Use just enough power. Once the dye is gone, extra power only heats the metal and can leave a yellowish or dull mark.
• Tight line spacing gives an even fill without stripes. Test the line interval on a scrap.
• Black anodizing gives the most contrast. Colours like red and blue look striking but sometimes leave a faint tint behind.
• Clean first. Fingerprints and oil show up in the finished mark. Wipe with isopropyl alcohol before engraving.

Photos and logos

Because the mark is lighter than the surface, a photo engraved as-is looks like a negative. The anodized aluminum preset in Photo Engrave inverts the image for you. Logos and text don’t need inverting: whatever is engraved shows bright.

Powder-coated tumblers and painted metal

Powder-coated tumblers work on the same principle: the laser removes the coating to show the steel beneath. They need a rotary and the right diameter; the tumbler wrap generator handles the layout and tells you the number to enter. Clean off the residue with a damp cloth afterwards.

Safety

Removing anodizing produces very little smoke, but vent the machine as usual. Metal reflects some laser light, so keep the lid closed and wear goggles rated for your laser’s wavelength on open-frame machines.

Settings

Starting values for anodized aluminum on diode, CO₂ and fiber lasers are on the xTool settings page and the other brand pages. A small test card on an offcut or the back of a blank finds the lowest power that gives a clean mark.