I would use an Image mode rather than Fill.
Image mode would require a black and white image.
I would recommend Grayscale mode, and this means the background needs to be 0xff black, rather than converting the red image to grayscale which would probably yield a 0x55 shade.
If instead you use Threshold mode, then red should still be OK. But there’s no option forward with variable depth in this mode. Variable depth may be need to slope the edges of the stamp features to avoid cutting the leather.
I did some test runs last night, here’s what I found:
Here’s a closer up image of the 50%, 500mm/s, .05 mm line interval stamp. You can see how the “Made in Texas” letters were damaged/warped. I think they were just too thin for the laser/acrylic to handle in this application.
I would say 100% power 1000mm/s and try 0.025mm LI. That should yield 2.25mm depth.
With that small of an LI, the bottom will be very smooth. At 0.1mmLI, it won’t be that smooth, but 0.05mmLI should still be smooth.
So, leave at 100% 1000mm/s and adjust depth with LI
@gordoa40: that is really useful information, thank you very much for plowing through all the different settings and conditions.
I don’t know what my next stamping project will be, but it sounds like at least a few of us could use a power/speed/interval matrix in acrylic. Most of the ones I’ve seen out there are greyscale squares so I’m thinking something that incorporates lines and text would be useful. Here’s a (really low-effort) PowerPoint mockup of the test design:
And/or include varying letter sizes. Then engrave a bunch of these designs in a matrix varying power/speed, labeling each setting in the design. We could deboss a few pieces of scrap leather with all the resulting stamps and mount both the matrix and the leather somewhere visible to everyone.
The things that would be hard to control for from one application to another are on the leather side: the temper, casing process, pressure applied… I think it could still be a decent starting point.
I’m happy to collaborate with anyone interested in creating a shared test design. I don’t have any particularly strong feelings about what it should look like other than making sure we vary the line thickness and include alphanumerics.
(I apologize for dropping out of the discussion for the last 10 days or so, it’s been an unpleasant time)
This type of testing and sample making sounds like a great idea. Having a starting point to work from is so helpful
This is an amazing post for exactly what I want to do! But, I have to say some of it is a bit above my head…I just reserved Tarkin from 11am-2pm tomorrow (10/19/26). I’m going to do a lot of experimenting with settings. If I come up with a good matrix sample of different settings I’ll leave it in the laser room. If anyone wants to join me for this little experiment, please do! I’m going to start with an image similar to the one @Branislav suggested in this thread (had straight lines, circles and text). I’ll also start with settings @dannym posted here. I know this post is pretty old, so I’m hoping things still work about the same.
the max depth is about 1/4 to 1/3 of the acrylic thickness if large areas are be removed.
the issue is the acrylic builds up too much heat in an area and starts to melt there. i tried a large, deep, detailed engraving with varying depth about about 50% average depth and the deepest part was about 70% of the material thickness with my settings. the acrylic warped and actually had the honeycomb pattern on thr front side because it melted and sagged into it
going slower seems to have little effect, it takes longer than that to shed the heat it’s picking up from cutting.
if the features are just narrow slot cuts, this probably won’t come up.
I’d be happy to go through the potential processes. I’m only available after work though.
There’s not one fixed workflow and settings. In fact this can be done as a Fill or grayscale depth map (3d relief capability) and each has its merits and limitations.
I started doing tests with a stamping handle and mallet, then thought a vise would give the best impression. I could see the leather stamp clicker press worked the best by far once I actually tried it.
After helping Lisa yesterday, here are my thoughts:
Used rastering three passes worked well on 1/2’ strudel acrylic that she had. The problem is that leaves sharp linear edges in the back ground that transfers to the leather once pressed. She was going to try adjusting line intervals and other things when I left.
The leather press may be another solution. Maybe she pressed too far. The result she got was a very even deep image sramp.
Maybe once you get enough depth rastering, you could finish with a couple of image passes to smooth the background. I did not try this yet but just my logic.
Lastly, rastering acrylic produces a lot of fumes and fine dust that eventually more than likely flashes back into the cone and lens so probably they would need to be cleaned. Also, if in the process of so many “try’s” the result starts to degrade, this may be the culprit.
The “play with fire” in me says to use a torch making quick passes to smooth the background but not sure if the image would survive. YOU ARE NOT ALLOWED to have open flames in Asembly so try it at home or outside. I also not aware of the flamability of cast acrylic.
After all this has anybody tried UDF/MDF or other materials to make stamps? Acrylic is not exactly the easiest material to work with.
Agreed – that clicker press is hugely powerful and could be part of the reason for the background to have transferred. I used other means (a 1-ton arbor press as well as vices in the woodshop) and didn’t have that problem. But again, the design / settings / depth of engraving all make a difference. It’s really hard to compare.
I should be able to measure the depth of my successful stamps once I’m back in town this weekend. @LisaKattawar, let me know if you think that might help.
