How to Engrave Photos on Glass with the xTool F2 and F2 Ultra UV

Photos on glass are one of my favorite things to make, and one of the easiest to get wrong. I've done a lot of testing on glass coasters and cups with two machines: the xTool F2, which needs a coat of paint on the glass, and the xTool F2 Ultra UV, which engraves straight onto it.

This guide brings three of my videos together: the F2 photo workflow above, my F2 Ultra UV glass photo video, and Never Waste Glass Again, where I tested different coatings. Jump to the machine you've got.

Jump to: Which method? · Raise the glass · F2: coat the glass · F2: set up in Studio · F2: photo settings · F2: text and designs · F2 Ultra UV: focusing · F2 Ultra UV: photo prep · F2 Ultra UV: settings · Tips

Which method do you need?

Glass is transparent, so most of the light from a laser passes straight through it without leaving a mark. How you deal with that depends on your machine:

• xTool F2 (blue diode): you coat the glass in tempera paint first. The paint gives the beam something to react with, and once you wash it off you're left with a white frosted engraving.
• xTool F2 Ultra UV: no paint, no spray, nothing. It engraves directly onto the glass and gives a frosted finish. The trick here is focusing, which I cover below.

Both methods work on flat glass coasters and on cups. I bought my coasters on Amazon in packs of four and six, round and square, and they're fairly cheap. The cups were cheap ones from a local supermarket.

Raise the glass off the bed (both machines)

This bit is really important, so don't skip it. Because the beam goes through the glass, if you put a coaster flat on the base plate the laser will pass through and mark the plate underneath. You need to lift the glass far enough that the beam spreads out before it reaches the bottom.

You could use the cutting plate or a dedicated jig. I use my self-centering jig. The screws in the middle hold the coaster high enough off the bed that nothing underneath gets marked, and because the jig centers the item, the coaster ends up in the middle every time.

On the F2 Ultra UV I used the same idea, with the coaster sitting on the standoffs. If you've got an F1, F2 or F1 Lite, that's the Self-Centering Jig. For the F1 Ultra, F2 Ultra and F2 Ultra UV it's the XL Self-Centering Jig.

The coasters come with little rubber feet, so check which way up yours is before you start. I engrave on the top face.

xTool F2: coat the glass

You'll need black tempera paint, a standard paintbrush (nothing special, I just like a wide one), a cheap pot to pour the paint into, and something to paint on so you don't make a mess.

Why tempera? I also tested chalk markers and the spray can version of the same stuff. No matter what I tried, I got flaking, chipping and a rough finish. With tempera paint the finish was clean, consistent and smooth to the touch, and my test glass came through the dishwasher fine.

1. Give the glass a wipe with an alcohol spray first so there are no fingerprints.
2. Pour a little paint into your pot. It goes a long way.
3. Brush on a coat with no clear gaps. On coasters I cake it on thick, and my photo settings below are set up for that. On cups for text and designs, aim for an even coat, because thick patches are harder to engrave through.
4. If you're only marking a small area of a cup, you only need to paint that area.
5. Let it dry. In my experience that takes 30 to 40 minutes, so if you're doing a batch, paint them all at once and leave them on the side.

The paint flattens out as it dries. If a bit comes through onto the bottom, it cleans off afterwards.

xTool F2: focus and set up in xTool Studio

Focusing is easy here because the painted surface isn't transparent any more. Turn the focus knob on the side of the F2 (left, in my case) until the two dots join together. That's you focused on the top surface. You can also use the auto measure button in xTool Studio if you'd rather.

1. Click New project in the top right. Studio connects to the F2 and takes a photo of the bed.
2. Click Unknown material at the top of the right panel and pick Clear Soda-Lime Glass, then Apply. This matters later, because Studio adjusts the photo based on the material you've chosen.
3. Import your photo with the plus symbol on the left.
4. Remove the background. A background washes the photo out on glass, slate and even stainless steel, because there isn't enough contrast to make the person pop. The Cutout tool in Studio is good on simple photos. For a busy photo I use the free background remover on Adobe Express, then import the result.
5. For a round coaster, select the photo, click Mask in the top toolbar (or right-click and choose Create mask), pick the circle and drag it to where you want it. Click Done, then center the image on the coaster.
6. Click Adjust and then Auto adjust. Because you picked soda-lime glass, Studio inverts the image and sets the contrast, sharpness and brightness for you.

Why invert? Where the beam hits the glass it turns white, and dark areas are left almost clear. If you didn't invert it, your engraving would look like a photo negative.

One tip on the adjust panel: large white areas end up transparent on the glass. If your photo has a lot of them, bring the brightness down a little so they become more of a gray.

Then frame it. Click the framing button in the bottom right, choose Outline so you see the actual shape of the photo, set the light power to 10, and run it. The camera photo on the F2 is good, but framing every time is a good habit.

xTool F2: photo settings

I ran a lot of image material tests on different coasters to get to these, testing refined settings and different numbers of passes.

Two passes are there because of the thick paint. One pass won't burn through enough to give you real clarity. My coaster took 11 minutes 28 seconds. When you click Process, the preview shows the photo the right way round again. Don't panic, it still engraves inverted.

Paint thickness and glass type are variables, so treat these as a baseline. If the engraving looks washed out before you take it off the bed, run a third pass. The passes are what burn off the paint and give you the clarity.

Use the blue laser with the lid closed, or wear laser safety glasses if the lid has to be open. Glass and paint make dust, so have your extraction running. When it's done, wash the paint off with warm water.

xTool F2: text and designs on a glass

For text and SVG designs on a cup, the process is the same: coat, raise, focus, frame. My pint glass had a tapered side, so I held it in the self-centering jig with a bit of Blu-Tack underneath to keep it level.

Keep the design narrow on a narrow glass. On a curve, the beam hits the edges at an angle and doesn't mark properly. On my glass, about 30 mm wide was the maximum. With the glass in the jig it's already centered, so line your design up with the middle line on the canvas.

That job took 1 minute 40 seconds. If you went heavy on the paint and it doesn't look right, add a second pass. A tall glass sits higher than the enclosure, so wear your laser safety glasses for this one.

Run it under hot water and give it a wipe, and you're left with a smooth white finish with no chipping. Holding something dark behind the glass really shows the contrast.

xTool F2 Ultra UV: focusing on clear glass

No paint needed on the F2 Ultra UV, but focusing is harder. When you look at the focus dots on bare glass, they've gone straight through the material onto whatever's underneath, so it's hard to tell when you're on the top surface.

1. Lay a normal sheet of paper on top of the glass. Now you can see the dots.
2. Use the arrows on the touch control to move until the dots come together.
3. Press the paper down flat while you check. It can look focused when it isn't quite. Once it's joined with the paper pressed down, take the paper off.

Then finish the job in xTool Studio:

1. Click New project so Studio connects and updates the photo.
2. Set the material to Clear Soda-Lime Glass and click Apply. It's the closest match in the xTool library. The height number will change when you do this.
3. Put the paper back on, adjust the focus again with the paper pressed down, and the number updates. Mine read 53.7 mm.
4. Subtract the thickness of the paper. Mine is 0.1 mm, so I typed in 53.6 mm.

Now you're focused on the top surface of the glass. Some people defocus on purpose. I focus directly on the surface.

xTool F2 Ultra UV: photo prep

Import your photo with the plus symbol on the left. Again, remove the background if it has one. I also use the Crop button to bring the bounding box down to the top of the head, so a rectangular frame shows the true size of the photo. A circular mask works the same way as on the F2 (right-click, Create mask, circle, Done). With the glass in a self-centering jig, select the image and use Align then Align center, and it's centered on the coaster.

Normally I'm a fan of Auto adjust. On the F2 Ultra UV, though, I found it made the photo too bitty and too light, so the light went straight through and it didn't stand out. I adjust it by hand. Click Adjust, then:

1. Tick Invert. This is critical on glass. Light areas get very little power and stay almost clear. Dark areas get more power and turn into a white frosted finish.
2. Set Contrast to -10. It adds a slight cloudiness, but that helps it pop when it engraves.
3. Set Brightness to -10. You want as little pure white as possible, because white means transparent. Light hair should go from white to gray.
4. Set Sharpness to 10 to win back the detail you lose by lowering contrast and brightness.
5. Tick Grayscale if your photo is in color.

Every photo is different, so treat those numbers as a starting point and tweak from there.

For framing, select the image, click the three dots next to framing in the bottom right, and pick a rectangular outline. I set light power to 10 so I've got every chance of seeing it. The frame line goes through the glass too, but if you look at the coaster from an angle you can see it on the top face. If you're not sure, lay your paper back on top and check against that.

xTool F2 Ultra UV: photo settings

The default Clear Soda-Lime Glass settings came out washed out and faded for me. These are the ones I landed on after a lot of testing, saved as my own material in the library.

My square coaster took 13 minutes 20 seconds with two passes. One pass halves that to just under 7 minutes and still looks good. Two passes look excellent. Your call.

Glass makes a lot of fine dust and offcuts on this machine, so use a pre-filter and extraction, and keep the lid closed or wear safety glasses if it has to be open.

Tips for better glass photos

• Always lift the glass. It protects your base plate on both machines.
• Kill the background before you do anything else with the photo.
• Watch the white areas. White means clear glass. Lower the brightness until they're closer to gray.
• F2 looking faded? Run a third pass to clear the last of the paint.
• Try a scrap first. A cheap coaster is a lot less painful to lose than a gift.

All my tested settings are in the free Laser Settings Library. There's a page for xTool F2 glass settings and one for the xTool F2 Ultra UV.

What are you putting on glass?

Let me know in the comments on the video how your first one turns out, and if you get stuck on a step, tell me where and I'll help where I can.