Leather Quality and Properties

[j ingevaldsson]

^^^ As vmss says, Vegano is just the name for Annonay’s main chrome tanned burnishable crust calf (with Vocalou being their main aniline calf).

Without knowing, I’ve thought the reason we see much less veg tan calf used for shoe uppers is that the smaller skins becomes too “sensitive” to be ideal, works better for sturdier, thicker older hides. Cause the full veg calf I know off almost always seem to be used only for linings or women’s shoes etc, or other products, not shoe uppers.

Regarding the environmental concerns, I would be really interested to see comparison between the European chrome tanned leathers (where the very strict regulations make sure they have closed systems and nothing is released out to nature. If the leather is not burned when disposed, basically no chrome will end up in nature) and European vegetable tanned leather, where a lot of water is used during the tanning. We often talk about how the heavy use of water is one of the big environmental problems with cotton production, even if it’s done in a green way otherwise, but this discussion never comes up when it comes to leather. Also add a comparison on how the plastic based “vegan leathers” environmental impact, I’m at least quite certain the latter would be way worse than the two others.

 

[ntempleman]

There’s some Italian tanneries doing fully veg tan, I’ve used Tempesti Malta calf butt a few times. Bakers “Russian” calf is fully veg. Veg tan always has a sort of rustic quality from what I’ve seen, and it isn’t better or worse, just better suited to some applications. There’s a few places doing veg retanning of chrome leather, Haas, Degermann, my Du Puy lining is a veg retan. Sometimes I feel like veg tanned leather gets this reputation as the pinnacle or whatever and I’m not sure why. I would liken it to a hand woven tweed against a tightly worsted Super 150 - one is better for a suit, the other will be a better sports jacket

 

[DWFII]

^^^ As vmss says, Vegano is just the name for Annonay’s main chrome tanned burnishable crust calf (with Vocalou being their main aniline calf).

Without knowing, I’ve thought the reason we see much less veg tan calf used for shoe uppers is that the smaller skins becomes too “sensitive” to be ideal, works better for sturdier, thicker older hides. Cause the full veg calf I know off almost always seem to be used only for linings or women’s shoes etc, or other products, not shoe uppers.

Regarding the environmental concerns, I would be really interested to see comparison between the European chrome tanned leathers (where the very strict regulations make sure they have closed systems and nothing is released out to nature. If the leather is not burned when disposed, basically no chrome will end up in nature) and European vegetable tanned leather, where a lot of water is used during the tanning. We often talk about how the heavy use of water is one of the big environmental problems with cotton production, even if it’s done in a green way otherwise, but this discussion never comes up when it comes to leather. Also add a comparison on how the plastic based “vegan leathers” environmental impact, I’m at least quite certain the latter would be way worse than the two others.

Well, again, chrome salts are poisonous. So much so that there are individuals who are so allergic that they react to the finished leather just being up against the skin--as in wearing shoes or boots. Moisture such as perspiration, can leech chromium salts out of the leather.Rainwater will as well. That's one of the reasons I use veg lining almost exclusively.

And, whether the tannery's process is careless or not some chrome is going to end up in the environment if only from all the discarded shoes. But water is a necessary resource for any kind of tanning and eliminating the chrome from the water entirely is always going to be problematic.

That said, some years ago I began to explore veg tan upper leathers (getting back to our roots) and as I mentioned the interest is there--esp. in Europe. And there are some very nice, dressy veg tans coming down the pipe. Not all modern veg tans are tanned with oak or chestnut or at least not exclusively so--berries, fruit, roots, leaves, etc., of various previously unheard of plants, are being used to produce results that sometimes are very different than traditional veg tans

I can't really say for certain what reservations, if any, are holding back the process...but here are two tanneries that produce veg tanned leathers for shoes and boots:

Sorenson (also produces chrome tanned leather)

Ecopell (my wife has a pair of shoes made from this leather, although most of this is a little rustic)

I suspect that the main reason chrome tans dominate is that vegetable tans tend to have more residual oil and / or fat liquor which prevents bright finishes from being applied. Also chrome tanning leaves the leather 'blue'--a grey verging on white--so dye colours tend to be clearer and brighter than on the tans and browns commonly associated with veg.(although some newer veg tanned methods yield a nearly pure white leather). Both factors--the oils and the colour of the rough stock--contribute to the 'rustic' appearance of veg...or at least the perception of rusticity.

Finally, I don't think it is the size of the animal that determines whether vegetable tannage is going to be appropriate or not. Most leather from young animals is tight and less porous than older hides...so better quality leather results regardless of the tanning agents. Lining leather is often smaller hides --kips (an older calf...most calf skins today are probably closer to being kips than what Traditionally was considered calf--Thornton in particular speaks to this) . And in the 19th century when chrome tanning was virtually unknown smaller skins were preferred for high quality goods.

 

[j ingevaldsson]

Well, again, chrome salts are poisonous. So much so that there are individuals who are so allergic that they react to the finished leather just being up against the skin--as in wearing shoes or boots. Moisture such as perspiration, can leech chromium salts out of the leather.Rainwater will as well. That's one of the reasons I use veg lining almost exclusively.

And, whether the tannery's process is careless or not some chrome is going to end up in the environment if only from all the discarded shoes. But water is a necessary resource for any kind of tanning and eliminating the chrome from the water entirely is always going to be problematic.

That said, some years ago I began to explore veg tan upper leathers (getting back to our roots) and as I mentioned the interest is there--esp. in Europe. And there are some very nice, dressy veg tans coming down the pipe. Not all modern veg tans are tanned with oak or chestnut or at least not exclusively so--berries, fruit, roots, leaves, etc., of various previously unheard of plants, are being used to produce results that sometimes are very different than traditional veg tans

I can't really say for certain what reservations, if any, are holding back the process...but here are two tanneries that produce veg tanned leathers for shoes and boots:

Sorenson (also produces chrome tanned leather)

Ecopell (my wife has a pair of shoes made from this leather, although most of this is a little rustic)

I suspect that the main reason chrome tans dominate is that vegetable tans tend to have more residual oil and / or fat liquor which prevents bright finishes from being applied. Also chrome tanning leaves the leather 'blue'--a grey verging on white--so dye colours tend to be clearer and brighter than on the tans and browns commonly associated with veg.(although some newer veg tanned methods yield a nearly pure white leather). Both factors--the oils and the colour of the rough stock--contribute to the 'rustic' appearance of veg...or at least the perception of rusticity.

Finally, I don't think it is the size of the animal that determines whether vegetable tannage is going to be appropriate or not. Most leather from young animals is tight and less porous than older hides...so better quality leather results regardless of the tanning agents. Lining leather is often smaller hides --kips (an older calf...most calf skins today are probably closer to being kips than what Traditionally was considered calf--Thornton in particular speaks to this) . And in the 19th century when chrome tanning was virtually unknown smaller skins were preferred for high quality goods.

Yes, chrome salts are poisonous. But you also now do what I'm sceptic against, that "chrome tanned" is bundled together as one thing, something we don't do with for example cotton.

To just go through some examples, how the chrome tanning is done matters a lot in how the properties for final product will end up being, if lower amounts are used and the tanning is "finished off" properly and hides thoroughly washed and treated, the release of chrome when wet will be very, very minimal (that's why I said "basically no chrome will end up in nature". I've read a study of the levels of chrome on newly tanned leathers and then compared to how much is left in old shoes, and the amount of chrome was more or less the same. Don't remember where it was from, will see if I can find it again). The same with those who are sensitive to chrome, if it's tanned in a good way, as described above, they have no problems with it, while they can react heavily to badly tanned chrome leathers. But you can't compare very quickly and badly tanned chrome leathers from tanneries with very bad cleaning systems in for example India or Bangladesh, to some of the best tanned chrome hides from European tanneries with their completely closed systems. It's sort of like comparing thick oak bark tanned leather soles with super soft upholstery leather, they're both veg tanned, still two very different things.

As I assume is common knowledge, the trivalent chrome used when tanning leather is much less harmful than the hexavalent chrome. If burned though, the trivalent chrome turns to hexavalent chrome, that's why you should always dispose your chrome leather products as "harmful material". If you do that, and it's good quality chrome tanned leather from good tanneries, again, the amounts of chromium released to nature is almost none.

That's why I said I was interested in seeing the comparison between these good chrome tanned leather's environmental impact to vegetable tanned leathers. I mean, using quite small amounts of water when tanning 1-2 days (which is the average time chrome tanned hides are tanned) compared heavily use of water when tanning for about 2 months (which is some sort of average time that vegetable tanned leathers that can be used for uppers are tanned) have to mean something, otherwise, why would we talk so much about the environmental problems with use of water in cotton production?

I know you often talk about how only vegetable tanned leathers was used back in the days, but as we discussed before, all development doesn't have to be bad, right? I mean, the tools used when making shoes even further back in the days were ****, no one would want to use that today, the development of tool production has been a positive thing. In the same way, the development of tanning can be a positive thing as well (I mean, yeez, I would definitely not want to go back to the super heavily chrome used real aniline dyed extremely poisonous leathers used for shoes at one time in history).

Now note, I don't have anything agains vegetable tanned leathers for uppers, I myself have made a special edition boot with Vass using vegetable tanned leathers from a Swedish tannery, and have boots in veg tanned leather. As Nicholas said, for some shoes it's excellent, for some chrome tanned are better. Maybe new types of veg tanend leathers will be just as good as chrome tanned hides also for dress shoes, great then. But I don't like how the discussion on chrome tanned vs veg tanned is almost always so black and white, wrongly so, IMO.

 

[florent]

Here is a study comparing environmental footprints of leather coming from different tanneries.
Conclusion is basically that magnitude of differences is higher between tanneries than between chrome vs. veg tanning and you can't designate a winner between the two.

There are several weaknesses in this study but it still is the most robust publicly available afaik

 

[DWFII]

That's why I said I was interested in seeing the comparison between these good chrome tanned leather's environmental impact to vegetable tanned leathers. I mean, using quite small amounts of water when tanning 1-2 days (which is the average time chrome tanned hides are tanned) compared heavily use of water when tanning for about 2 months (which is some sort of average time that vegetable tanned leathers that can be used for uppers are tanned) have to mean something, otherwise, why would we talk so much about the environmental problems with use of water in cotton production?

Now I'm neither a tanner nor a chemist, but think about it for a second...how did people discover that leather could be tanned with bark? Maybe it was some once-in-an-epoch epiphany by some one-in-a-million genius, but I suspect it's more likely the gradual realization (over generations) that sometimes dead animals lying in pools of water in heavily forested areas didn't decompose as readily as if lying in the open. What does that suggest? For me, it says that pools of dark brown, heavily tannic, 'tea' water are pretty much a common and a natural occurrence. And that overall, such pools and such extracts are, if not harmless to the environment, at least only mildly so.

You can't say that about chromium...and yes chromium occurs in nature but so does arsenic. AFAIK, oak bark is not even in the same league. You can't compare the toxicity.

I mean, the tools used when making shoes even further back in the days were ****, no one would want to use that today,

And that's so completely off base as to almost be laughable. Unless you want to go back to prehistoric times. Most bespoke makers would rather use old tools than new. We all have a collection of antique and vintage tools. I have tools that go back to the 1700's. I treasure them. In many cases, I wouldn't give a plug nickle for the modern equivalents of the tools I use unless they were made to the same or similar specification as the old tools.

 

[vmss]

Yes, chrome salts are poisonous. But you also now do what I'm sceptic against, that "chrome tanned" is bundled together as one thing, something we don't do with for example cotton.

To just go through some examples, how the chrome tanning is done matters a lot in how the properties for final product will end up being, if lower amounts are used and the tanning is "finished off" properly and hides thoroughly washed and treated, the release of chrome when wet will be very, very minimal (that's why I said "basically no chrome will end up in nature". I've read a study of the levels of chrome on newly tanned leathers and then compared to how much is left in old shoes, and the amount of chrome was more or less the same. Don't remember where it was from, will see if I can find it again). The same with those who are sensitive to chrome, if it's tanned in a good way, as described above, they have no problems with it, while they can react heavily to badly tanned chrome leathers. But you can't compare very quickly and badly tanned chrome leathers from tanneries with very bad cleaning systems in for example India or Bangladesh, to some of the best tanned chrome hides from European tanneries with their completely closed systems. It's sort of like comparing thick oak bark tanned leather soles with super soft upholstery leather, they're both veg tanned, still two very different things.

As I assume is common knowledge, the trivalent chrome used when tanning leather is much less harmful than the hexavalent chrome. If burned though, the trivalent chrome turns to hexavalent chrome, that's why you should always dispose your chrome leather products as "harmful material". If you do that, and it's good quality chrome tanned leather from good tanneries, again, the amounts of chromium released to nature is almost none.

That's why I said I was interested in seeing the comparison between these good chrome tanned leather's environmental impact to vegetable tanned leathers. I mean, using quite small amounts of water when tanning 1-2 days (which is the average time chrome tanned hides are tanned) compared heavily use of water when tanning for about 2 months (which is some sort of average time that vegetable tanned leathers that can be used for uppers are tanned) have to mean something, otherwise, why would we talk so much about the environmental problems with use of water in cotton production?

I know you often talk about how only vegetable tanned leathers was used back in the days, but as we discussed before, all development doesn't have to be bad, right? I mean, the tools used when making shoes even further back in the days were ****, no one would want to use that today, the development of tool production has been a positive thing. In the same way, the development of tanning can be a positive thing as well (I mean, yeez, I would definitely not want to go back to the super heavily chrome used real aniline dyed extremely poisonous leathers used for shoes at one time in history).

Now note, I don't have anything agains vegetable tanned leathers for uppers, I myself have made a special edition boot with Vass using vegetable tanned leathers from a Swedish tannery, and have boots in veg tanned leather. As Nicholas said, for some shoes it's excellent, for some chrome tanned are better. Maybe new types of veg tanend leathers will be just as good as chrome tanned hides also for dress shoes, great then. But I don't like how the discussion on chrome tanned vs veg tanned is almost always so black and white, wrongly so, IMO.

is there any truth to this statement that chrome leather will crack sooner than later and that veg tan leather doesn't deal with crack issues?
"It also adds to vegetable tanned leather products impressive ageing and longevity, whereas the chrome tanned products will wear badly and crack sooner rather than later."https://www.axesswallets.com/blogs/blog/vegtan-vs-chrometan

 

[j ingevaldsson]

Now I'm neither a tanner nor a chemist, but think about it for a second...how did people discover that leather could be tanned with bark? Maybe it was some once-in-an epoch epiphany by some one-in-amillion genius, but I think it was more likely the observation that sometimes dead animals lying in pools of water in heavily forested areas didn't decompose as readily as if lying in the open. What does that suggest? For me, it says that pools of dark brown tannic heavily 'tea' water are pretty much a common and a natural occurance. And that overall, such pools and such extracts are if not harmless to the environment, at least only mildly so.

"I mean, the tools used when making shoes even further back in the days were ****, no one would want to use that today,"


And that's so completely off base as to almost be laughable. Unless you want tgo back to prehistoric times. Most bespoke makers would rather use old tools than new. We all have a collection of antique and vintage tools. I have tools that go back to the 1700's. I treasure them. In many cases, I wouldn't give a plug nickle for the modern equivalents of the tools I use unless they were made to the same or similar specification as the old tools.

But the development made it so that we don't tan leathers in pools on the ground anymore either. Veg tanned leathers today are (not always, but almost) industrial products. And it's a fact that a lot of water is used. This leather is also way, way better than those hides tanned in pools on the ground. Again, development isn't always bad...

Of course I know that today's tools are, in general, ****. I've written blog posts about it and bashed the lack of good material for tool makers today, etc. That doesn't change the fact that time developed tools to be better for making shoes. All development isn't bad. When I say all development isn't bad, that doesn't mean that all development is good either you know..

 

[j ingevaldsson]

is there any truth to this statement that chrome leather will crack sooner than later and that veg tan lrather doesn't deal with crack issues?
"It also adds to vegetable tanned leather products impressive ageing and longevity, whereas the chrome tanned products will wear badly and crack sooner rather than later."https://www.axesswallets.com/blogs/blog/vegtan-vs-chrometan

I've seen badly cracked leathers of all kinds, chrome tanned as well as veg tanned.

 

[DWFII]

But the development made it so that we don't tan leathers in pools on the ground anymore either. Veg tanned leathers today are (not always, but almost) industrial products. And it's a fact that a lot of water is used. This leather is also way, way better than those hides tanned in pools on the ground. Again, development isn't always bad...

I didn't say all development is bad. Thoughtless, ignorant development....never asking the question of whether it is appropriate or even needed...not so much.

And as far as pools of tannic water...tell thaat to Baker or any of a number of 'old school' tanners--that's exactly how such leather get tanned--sitting in deep pools (cement encased pools) of extract.

And I don't buy the fact that water used in veg tanneries is all that environmentally harmful--again, for millions of years pools of tannic extracts have seeped into the ground with no one the wiser, no tree-huggers (God bless them) running hysterically around pulling their hair.

 

[ntempleman]

Look at any insole of an old shoe to see that veg tan leather will crack just as readily as any other. Tanning with metallic salts like chrome is nothing new, aluminium was used probably before vegetable tannins ever were

 

[j ingevaldsson]

I didn't say all development is bad. Thoughtless, ignorant development....never asking the question of whether it is appropriate or even needed...not so much.

And as far as pools of tannic water...tell thaat to Baker or any of a number of 'old school' tanners--that's exactly how such leather get tanned--sitting in deep pools (cement encased pools) of extract.

And I don't buy the fact that water used in veg tanneries is all that environmentally harmful--again, for millions of years pols of tannic extracts have seeped into the groundno one the wiser, no tree-huggers (God bless them)m running hysterically around pulling their hair.

Those pools that Baker and others use carry quite heavy loads of water, and they are passed between various baths with heavy loads of water, and that water is exchanged, etc, they are not really comparable to those "pools in the ground" you mentioned..

I don't talk about the water from veg tanned being harmful, I'm talking about the high amounts of water used being problematic from an environmental perspective. Same discussion as in cotton production (although I would believe cotton is much worse in this matter than veg tanned leather, but how much, I don't know. That's why I say would like to see a comparison between good chrome tanned and veg tanned from an environmental perspective).

Look at any insole of an old shoe to see that veg tan leather will crack just as readily as any other. Tanning with metallic salts like chrome is nothing new, aluminium was used probably before vegetable tannins ever were

I don't believe aluminium was used before vegetable tannins, but way back in history, yes.

 

[DWFII]

Look at any insole of an old shoe to see that veg tan leather will crack just as readily as any other. Tanning with metallic salts like chrome is nothing new, aluminium was used probably before vegetable tannins ever were

Well, I doubt that...at least by itself...but alum certainly was pretty early.

However, "By itself, "alum" often refers to potassium alum". And it was this form that, if I understand correctly was used in Ancient times.

That said, brain/smoke tans, as well as veg tans, may go back into pre-history.

 

[j ingevaldsson]

Here is a study comparing environmental footprints of leather coming from different tanneries.
Conclusion is basically that magnitude of differences is higher between tanneries than between chrome vs. veg tanning and you can't designate a winner between the two.

There are several weaknesses in this study but it still is the most robust publicly available afaik

Missed this post. Interesting, thanks! Will check through.

 

[DWFII]

I don't talk about the water from veg tanned being harmful, I'm talking about the high amounts of water used being problematic from an environmental perspective.

I'm not sure how...the extracts that colour the tanning waters are organic in nature. And in pools such as bogs (Otzi) that water is ground water and it eventually it seeps into the soil and joins other natural waters fed by rain and springs and so forth. We've been living with bogs and drinking ground waters that are at least partially mixed with extracts of vegetable matter for thousands and thousands of years. Our ancestors didn't have Brita filters. And, unless the current craziness is somehow connected, apparently without noticeable ill effects--either for us or for the environment.