I’ve read all the posts touting veg tanned leather and warning against chrome tanned. My question is how do you know the difference? I was given a leather wrapped flask and a leather money clip to engrave. The packaging on both states simply “genuine leather”. How do I know whether or not it’s safe? Err on the side of caution?
You’ve missed a couple because I’ve posted the below more than once I’m just too lazy to go find them
You can tell the difference by putting a small strip in boiling water. Veggie tan will curl up almost instantly. Chrome tanned will float without insta-curling.
Or (I use this more because it’s quicker but it requires a bit of subjectivity and knowledge having known samples before - due to the “more easily” test of the flame test…if you don’t have some of each you won’t know if it’s “more easily” until you get a sample that burns differently)
Burn a piece with a lighter - veggie tanned won’t burn with flames and will leave black or grayish ashes. Chrome tanned burns more easily and leaves green ashes.
If you have the ability, I HIGHLY recommend finding a local leather shop to visit (Tandy or something similar) and asking your question there. I’ve found the best and quickest way to learn about leather is from leatherworkers who have spent years dealing with it. I learned more in a 45minute visit than I did in weeks of online research.
Some highlights: When comparing differently tanned leather in person, it’s usually fairly obvious what the tanning process has been. Although milling and stamping can throw some curveballs in there. Oil tanned leather is also supposed to be chrome free and ‘safe’ for lasering (but I have not verified or tested). Most of what you come across in a retail setting will not be veg tanned, simply because it has an unfinished look and is intended for further processing. Craft supplies and blanks may be, but will usually note it specifically or say that they are ‘laserable’.
Don’t know if that helps or not, but a little general knowledge never hurt right?
Can’t exactly boil or burn 2 items that don’t belong to me. I guess I’ll just tell my customer that I can’t do it without being sure.
Yes, I’ve purchased through Tandy before. However, this question was in regards to 2 items brought to me by a customer. The packaging simply states “genuine leather”. I was hoping there was a damage-free way of testing something brought in by a customer.
There is but it’s really subjective - there is a different feel and look to chrome vs veggie but it’s like trying to explain yellow vs gold coloring. If you go get some known samples you’ll be able to see the difference.
For what it’s worth, there are probably two definitions of safe here.
Is it safe for the machine? If it’s genuine leather, yes. Some leather fabrics can be PVC-based. They will release chlorine which can be potentially harmful to your machine when it’s exposed to natural water content in the air.
The second aspect of, is it safe: is it safe for you? The fear here comes from the chromium (chrome tanned - chromium). People hear chromium and immediately go to hexavalent chromium. But there is also trivalent chromium.
Hexavalent chromium is dangerous and that’s why occupational/permissible exposure limits exist, and why a lot of care is taken to minimize exposure to it.
Trivalent chromium is actually an essential element in humans. We get it through food, water, etc.
So, I’m not a chemist… I don’t know exactly what happens when you laser chrome-tanned leather, and the potential transition from chromium III to chromium VI (hex chrome). I know that workers, such as welders, have portable air monitoring equipment that they wear when working that measures their exposure. The hex chrome elements stay active long enough to enter their breathing space and then can be breathed in - exposure.
So all in all, properly ventilated, with what you’re looking at to do a job, I wouldn’t hesitate to do it. But that’s just me and my personal risk level.
And another for what it’s worth:
This collar was latigo leather, which I’m pretty sure is chrome tanned and then veg tanned. Rio and I are both still kickin’.
From my fairly extensive reading of the posts here, what I have learned is that leather engraving has its issues. Will it engrave, yes. Will the sides and bottom of the engrave be charred and will that char discolor much of what touches it, generally yes. There are exceptions, but without a decent size piece of sacrificial material to experiment with the results posted to this forum suggest you would be pretty lucky to achieve good results on your first try. And that doesn’t consider dialing in settings for an unknown material.
It sounds like you have experience in knowing how to deal with unknown materials as you reference a customer. Please don’t take the above as a lecture, it was meant as much for the lurkers as anything else. Personally, I’m with jbmanning5 as regards leather-lasering-safety and am mainly concerned with how well a particular leather responds to being attacked with a laser and a lot of chrome/oil tanned leather is supposed to react poorly.
Yeah, I’ve actually had really good results using PG leather, on low power with the mask removed. Super clean engraves with no charring at all. But not knowing the composition or quality of this leather has me hesitant to try anything with it. While some feel that it is relatively safe with adequate ventilation, I have a teenager with breathing problems, so I’d rather be overly cautious.
I’ve used oil tanned, chrome tanned, veg tanned, and all sort of top coated/colored leathers, and only real issue is whether I need to mask it or not (if not sure, mask! Currently using masking tape, haven’t bought the specialty stuff yet–but first put the tape on a scrap piece to detact it a bit, and apply evenly). But good ventilation is key!
And pending the dye and color, you may get really good results or not with the contrast from the laser. And use a soft toothbrush to wash out the soot afterwards.