DIY Coatings for Glass Engraving: Which One Actually Works?
Engraving glass with a diode laser sounds cool until you try it and realize nothing happens. The laser beam passes right through the glass unless you coat it with something that helps it absorb heat.
Normally, I use Moly Dry Lube. It is affordable, works consistently on both glass and stainless steel, and performs almost as well as those expensive commercial marking sprays. But I ran out, and instead of buying more, I decided to test out what the internet claims actually works. I put four common DIY coatings to the test to see if any of them could give me the clean, frosted engraving we all want.
This is part one of a new series where I test everything from budget-friendly coatings to commercial sprays made specifically for laser engraving. Let's get into it.
The DIY Coatings I Tested
I chose four coatings that I saw recommended across forums, videos, and posts. These are materials many people already have in their garage, art supplies, or junk drawers:
Tempera paint
Acrylic spray paint
Chalk paint
Permanent marker (Sharpie-style)
No fancy products. No laser-specific sprays. Just stuff most people can grab at the store or already own.
The Setup
For this test, I used the xTool S1 40W diode laser and two small glass jars with flat sides. Each side of each jar got one coating. I labeled the bottoms with T, A, C, or M so I could tell them apart later.
I applied each coating and let it dry naturally overnight. No heat guns, no shortcuts. I wanted this to reflect a process that anyone could follow.
There were a few surprises early on:
I could not find a Sharpie. I had to settle for a different brand of permanent marker.
My tempera set was missing the black paint. I had to mix red, yellow, and blue by hand to get something close. It ended up more like dark purple than black, but it still worked.
Painting with a foam brush on glass? Way harder than I expected. I had to do two coats with the tempera because the first one went on patchy.
Despite all that, I was able to prep the jars, load a star pattern test in XCS, and start the engravings using a range of power and speed settings.
Engraving Results
Once everything was marked, I washed off the coatings and inspected the results. Here's how they performed:
Tempera: Easy to clean, strong contrast, great detail. This one impressed me from the start.
Acrylic: Darker results but inconsistent in the corners.
Chalk paint: Decent results, a little patchy.
Marker: The weakest performer, but still gave me visible markings.
Tempera clearly stood out. It produced a nice frosted finish and had the least number of issues. My wife agreed and picked it as the top performer in both the test grid and the real design engraving.
The Real Test: Tempera vs Moly
After tempera beat the other DIY coatings, I put it up against my usual choice — Moly Dry Lube.
I used the same glass, same settings, and the same design. One side coated in Moly, the other in tempera.
Both performed well, but Moly gave sharper, more consistent results. It is also easier to apply and does not require color mixing or foam brushes. That said, tempera gave it a run for its money and would make a solid backup if I am ever out of Moly again.
What I Learned
All four coatings worked, which was honestly a surprise.
Tempera was the best DIY option overall.
Moly still holds the top spot for performance and consistency.
Foam brushes are harder to use than they look.
Always check the box before you buy tempera — mine was missing black.
What’s Next
In my next test, I will be trying a professional laser marking spray that is made specifically for glass and metal. It is not cheap, and it is harder to find than tempera or Moly, but I am curious to see how it compares.
If you want to see how that test goes, make sure to subscribe to the YouTube channel or check back here for the full write-up.
Tools I Used (affiliate links)
All the tools I mention in my videos can be found on my Amazon Store
xTool S1 40W laser
RA2 Pro rotary tool
BORA folding workbench
Wagner spray booth
Purchases made through these links help support the channel and future tests like this one.
