Hopefully they will part with it.[quote=“marmak3261, post:115, topic:943”]
veteran garage sailors
[/quote]
Sorry, but, that made me laugh!!! 
I guess that would make me more of a garage pirate:
Ar-r-r-r-r-r-r Matey, what will you 'ave for that item thar?
@marmak3261 I have a huge stash of leather scraps, and I’d be happy to send you some to experiment with. Most of it is veg tan in varying weights, and I also have some garment leather as well (the latter is most likely chrome tan).
They won’t be huge pieces, but they’ll be good for experiments if you’d like to try them. If you’d like them just PM your address.
A little late to this discussion, but I thought that this might be useful or provide ideas.
While I await my Glowforge, I’m using a 100 watt Full Spectrum Laser.
The pictures below represent a test piece I made this week from 3 oz chrome tanned leather that I laminated to 1/8" plywood, then raster engraved, then laser cut. The piece is just under 2" in diameter.
On a 100w laser (again, not the 45w of a Glowforge), the raster settings used were speed 100, power 40. I wanted to go through the top dyed layer of leather, but not through the full leather into wood.
The vector settings were speed 80, power 60, 2-3 passes. I say 2-3 because I made a couple of these and I was ok with two passes on some, needed a third on one where I was almost but not quite through. The settings need a bit of tweaking so I can be sure it will cut each time.
We’ve got a good ventilation system and the fumes did not significantly smell, although I can’t speak to their actual toxicity. I can say that we’ve cut other items that smelled much worse and items from which the fumes made me cough for days while this had no issue over the 2 hours or so I was doing test cuts.
Awesome! I’m really happy to see this. I was assuming chrome tanned leather was going to be strictly no-no. For some reason I was thinking it just distintegrates into a gooey puddle, but maybe it’s oil-tanned that I’m thinking of. Regardless, this looks great!
Nice! This is great. I have some leather bracers Ive made that are a few layers of leather thick that Id really like to do do a new revision of. I want to engrave some cool designs into it. This is good motivation =)
A few notes on process for the Celtic discs might (or might not) be worth adding, and that may be useful in other situations.
I was willing to take on the risk of working with Chrome-tanned leather which gives off fumes, in part because I have a good filter and ventilation system for the laser, and in part because I’m totally up for a bit of risk in my life for the pleasure of making. Do your research and be sure you know and accept any risk before lasering Chrome-tanned leather.
The design came from https://openclipart.org/detail/264441/celtic-knot-5-optimized - openclipart.org has a large number of designs available as .svg files and all are available for use, including commercial, without attribution. I imported the design into Inkscape (also free) to size, to add the perimeter circle cut, and to differentiate what was to be raster engraved from vector cut.
I used blue painters tape on top of the leather so that the soot did not cover the un-rastered leather (tried without and was not happy with results and difficulty of removing the soot from the un-rastered sections).
Consider buying the 3" width of painters’ tape rather than the standard 3/4". For small pieces (under 3"), you won’t have to worry about overlap impacting the etching quality and you’ll have a nice clean unlined surface for viewing details in your work. For large pieces, you lessen the time to tape out significantly. And for all pieces, tape removal tends to be easier.
To remove the painters’ tape from intricate designs (without the tedium of tweezing), try a high-quality duck tape - stick it on securely to the blue painters’ tape after the piece is complete and rip it off quickly to get most of the blue tape off.
Duck tape also works for removing the extra soot from the perimeter edge - just roll the sticky side along the edge a bit like you were removing lint. I didn’t want the perimeter soot to rub off on people’s hands.
Duck tape will also work for removing most of the soot from within the design itself. I didn’t do that here, and am still looking for a dependable process for dying only the newly exposed portions black.
Woodweld works well for laminating chrome-tanned leather to wood.
To raster lightweight leathers with any intricacy, you’ll need some approach to keeping them flat and smooth. Seems obvious, but it’s a must.
The full piece took between 2 and 3 minutes to engrave then cut.
Thanks for the additional info! 
Yes, learned the hard way. Customer for custom furniture wanted his ranch brand on the chrome tanned leather. Working with metal, I thought ‘no problem’.
I reproduced his brand with 1/2" steel bar, and applied it to a scrap. The leather shrank and puckered around the hot iron like (ahem) a sphincter. 
Had to use spray adhesive to nail it down. I suspect gluing it to the backing saved your project.
Also, the finish on the leather cooked to ash, and I used an exacto knife to scrape it off, revealing a swade finish.
The finish left by the laser looks similar. Does the black scrape off like an ash?
I have a couple of full hides of the stuff, it would be nice if it didn’t present a hazard either mechanical or environmental.
As I recall, @morganstanfield, our own ‘leather Woman’ recommended against chrome tanned.
(Haven’t seen much of her lately, hope everything is going well for her.)
That is a beautiful Celtic knot, and very well executed! Going to make a sporran? 
I’ve read the info on Chrome tanned leather fumes and was personally willing to risk it but anyone reading this should definitely research for themselves.
The soot (the black) doesn’t exactly scrape off. Removing the blue tape takes some of the soot away on the design (as opposed to the outer rim where you have soot from both the leather and the wood), to the point where it didn’t come off on my fingers unless I rub aggressively. You can remove more of it with repeated use of duck tape - but you can’t get it all.
Any suggestions for how to fill in engraved sections only with ink or stain are very welcome!
This weekend, I’ll see if I can engrave and then cut a piece without the wood backing, then take a picture, just so that people may see what happens.
Cool 
Thinking the leather reaction to the laser heat will be much less than with a branding iron, but would be nice to know.
Thanks for sharing your experience! Lots of good info here, I really appreciate it.
Thanks, @printolaser! Yep, I’m fine–just hit month 8 of my “print job” and most of my energy is going toward the project. At this point, I’m either resting (because knitting an entire human being using only my internal organs is surprisingly exhausting), making baby stuff (felted cashmere-knit baby clothes and blankets from old sweaters, two leather diaper bags that convert to laptop bags, and a big sheepskin rug for the nursery are all on my project tables), or waddling through my daily obligations. I stop in here every day and use up my daily portion of likes, but posting is mostly beyond my allotment of spoons.
In the meantime, yeah, lasering chrome-tanned leather releases carcinogenic gas (hexavalent chrome is the main product, according to @jkopel), plus whatever nastiness is in the dyes and coatings, and the process generally ruins the leather. Gluing it to a backing can take care of shrinkage, but every variation in leather processing can produce a different result, and the result on lungs will be the same.
I too, was just thinking that you haven’t been around much. Good to hear some little details of your wintertime hibernation and the exciting and fun things you’re making for the new little one.
I can’t wait to meet your printout!
Congrats!
Thanks @Xabbess, @dan, and @jordanloshinsky! I’ll post pics after The Deed is done, and in the meantime enjoy your company on the down-low.
They are really cute sometimes… Sometimes
Your first right?
Excited for all three of you! I guess there won’t be any videos of you diving into snowdrifts this winter, though… 
