Period leather dyes?

[Harry Marinakis]

Anyone have any pointers on period leather dyes, other than brown and black, such as red, green yellow, blue, etc?

I've been fooling around with a lot of natural dyes, and am not having much luck dyeing leather.

I have been reviewing numerous references for period dyes, such as these:

Segreti per Colori
http://www.elizabethancostume.net/dyes/segreti.htm

Cleaning & Dyeing Recipes from The Secretes of the Reverend Maister Alexis of Piemont
http://www.elizabethancostume.net/dyes/alexis.html

A Profitable Booke
http://www.elizabethancostume.net/dyes/profitable.html

And I have this book, an English translation of a 15th C book that was the first ever treatise on dyeing techniques:

Plictho de l'arte de tentori, che insegna tenger panni telle banbasi et sede si per l'arthe magiore come per la commune
https://www.amazon.com/Plictho-Gioanven ... B001B3KDKM

Here's an example of a recipe from Segreti per Colori:

328. To dye scarlet.--Take 1/2 lb. of sandal wood and 1/2 lb. of madder, boil them together with plain water until reduced to one-half, and then add half a fogliecto of lye for its maestra to make the colour deeper, and a piece of quicklime, and boil it until reduced to one-third; then prepare the skins for dyeing as in the other recipes.

I have been learning the terminology and trying some of these recipes for dying "skins," but just learned that "skins" is synonymous with "skeines," which are bundles of linen or wool (not leather).

I've been trying Madder root, Brazilwood (Verzino), Old Fustic, etc., and have been throwing in all the mordants and other required agents in the various recipes like alum, quicklime, oak galls, gum arabic, tartar, etc.

Tonight I tried the above-quoted recipe for scarlet using powdered Madder root and Red Sandalwood (Padauk) but the dye did absolutely nothing to the leather. I even soaked the leather in the concoction without any coloration of the leather whatsoever. (Although it did dye my rubber spatula a nice deep red.)

Help?

[Primvs Pavlvs]

Could it because of modern tanning methods that's preventing the dye from "biting"?

[Thomas Powers]

How is your leather tanned?

[CTrumbore]

Could it because of modern tanning methods that's preventing the dye from "biting"?

It absolutely can be. Chrome or alum tanned is a bitch to dye.. that's why they do it during the tanning process, and waxed will, obviously, not take anything.

[CTrumbore]

If you are working with veg tanned leather (often called "oak" or similar), black is really simple.. iron filings (or steel wool) dissolved into vinegar. Just wipe it on and let it dry. A couple passes will give you an almost purple deep black. It's the iron reacting to the tannins in the leather (Same as an iron plane sole will react to wet oak.. or vice versa, really)

[Johann ColdIron]

If you are working with veg tanned leather (often called "oak" or similar), black is really simple.. iron filings (or steel wool) dissolved into vinegar. Just wipe it on and let it dry. A couple passes will give you an almost purple deep black. It's the iron reacting to the tannins in the leather (Same as an iron plane sole will react to wet oak.. or vice versa, really)

The period term for it is vinagroon. One of my students dyed some things he made that way and they turned out nice. I'm hoarding shop swarf for the next time I do a scabbard or something.

[CTrumbore]

If you are working with veg tanned leather (often called "oak" or similar), black is really simple.. iron filings (or steel wool) dissolved into vinegar. Just wipe it on and let it dry. A couple passes will give you an almost purple deep black. It's the iron reacting to the tannins in the leather (Same as an iron plane sole will react to wet oak.. or vice versa, really)

The period term for it is vinagroon. One of my students dyed some things he made that way and they turned out nice. I'm hoarding shop swarf for the next time I do a scabbard or something.

it makes oak a really fantastic black too.

[coreythompsonhm]

You may want to wipe the leather with denatured alcohol. Most likely it has been waxed if its a chrome tan.

[Harry Marinakis]

Thanks for the replies

I am using clean, undyed veg tan.

The brown and black dyeing is straightforward. Colors (like red and green) are giving me problems.

I am thinking that I need to soak the leather longer in mordants like alum or tartar, and soak the leather in the dye for a much longer period.

Here is my latest batch of red dye using a period recipe of
-crushed madder root
-red sandalwood shavings
-alum KAl(SO4)2
-oak gall (tannin)
-lye KOH
-limewater Ca(OH)2
-chalk Ca2CO3

And the leather swatches that I dyed.

As you can see, the leather dyed a brilliant red (not).
The two darker leather swatches on the right had a 1/4-tsp of vinagroon added to the red dye to see what it would do.
The solitary leather swatch at the bottom was the control.

[Primvs Pavlvs]

Harry, you have to be careful with modern "vegtan" especially if it's South American made stuff, it's not the same as the stuff made historically.

[Harry Marinakis]

Harry, you have to be careful with modern "vegtan" especially if it's South American made stuff, it's not the same as the stuff made historically.

Fine. My question still remains unanswered, how do you dye it with natural dyes?

[Ernst]

Perhaps you should be thinking of paint rather than dye?

[CTrumbore]

How long are you soaking them in the dye?

[CTrumbore]

How long are you soaking them in the dye?

I seem to remeber immesrsion for time being part of the process for many colors.

[Harry Marinakis]

So I have re-vamped by dye protocols and here is an update.

First, I soaked the leather in mordants like Roche Alum and Cream of Tartar (COT), as the tanins in leather do not seem to be adequate. Then I soaked the leather in the dye for much longer periods.

The Cream of Tartar was supposed to be the best mordant for leather, but my experiments are showing that Roche Alum is better.

Leather swatches were numbered LS20 through LS38.

The leather swatches were soaked for 2 hours in one of the following mordants: (1) Roche Alum, or (2) Cream of Tartar (COT), or (3) combined Roche Alum/COT, or (4) plain water (as a control).

Here is an update after soaking in a variety of dyes for 16 hours.

[Harry Marinakis]

This is a dye extract (Dye HM005) made from cheap Harbor Freight walnut blast media. The blast media was boiled for a few hours, then the solution was decanted. It is slightly acidic with a pH=6.

The combination of Alum & Cream of Tartar seem to be giving the best color.

[Harry Marinakis]

This is the same blasts media extract as above, but I neutralized the extract to pH=7 with bicarbonate (Dye HM004). It is a richer, darker brown. (Adding lye to make it slightly alkaline pH=8 was counter-productive.)

The Alum mordant seems to be giving the best color.

[Harry Marinakis]

This dye extract (Dye HM006) was made from Madder root. When trying to reduce the volume of the extract, I let it get too hot, so this may be a more "burnt" red than Madder should be. Using a period recipe, I added a dash of lye and some slack lime.

The different mordants do not seem to have made a difference, except Leather Swatch 38 (soaked in plain water not a mordant) seems to be slightly duller than the others.

[Harry Marinakis]

This is the same Madder recipe as above (Dye HM006), but I added a teaspoon of chalk to brighten the color. It seems to have worked.

The Cream of Tartar mordant, and the water-soaked leather swatch, seem to be slightly duller than the others. Again Roche Alum seems to be the best mordant.

[Harry Marinakis]

This is a saturated vinagroon dye at 16 hours. Yesterday the swatches were light grey, but today they are dark gun-metal blue/purple, not a black.

Period recipes call for adding fresh walnut extract to vinagroon to get a nice dark color, but I'll have to wait for September to harvest fresh walnuts.

Again, the Roche Alum seems to be the best mordant for leather.

[jester]

Images of modern dyers using medieval techniques (India, North Africa) appear to show a very, very flexible leather (like cloth). Is it possible leather was being dyed earlier in the process?

[Harry Marinakis]

Is it possible leather was being dyed earlier in the process?

Yes, in period leather was often (but not always) dyed during the tanning process.

A lot of period recipes also call for soaking the leather in boiling dye. This would harden the leather (cuir bouilli), unless perhaps this was done as part of the tanning process. I am not familiar with the process of tanning, so perhaps someone else could comment on whether or not skins were boiled during tanning. If so, this would be when the skins were dyed.

Other dyes (like Madder root) are less vibrant if heated all the way to a boil.

[Harry Marinakis]

Final chapter here, boys and girls. After the leather soaked in the dye extracts for 2 days, I pulled the plug to see what I got.

Lessons Learned:

1. Work all of your calculations and measurements in terms of WOL (Weight of Leather), i.e., the weight of the leather that you are going to dye.

2. After you've extracted the colorant and you have a a couple of liters of colored water in your pot, then what? I had an epiphany: While you cannot actually measure the concentration of color in your final dye extract, you can use a proxy. Here's my epiphany:

Weigh your dry substrate before you dump it in the pot of water. For example: Put 100 grams of Brazilwood into a pot with 2 liters of water and extract the colorant with soaking and boiling. Remove the plant material and then reduce the dye bath volume down to 100 ml with a slow simmer. That gives you a dye concentration of 100 grams of Brazilwood in 100 ml of solution, or 1gm/ml. This is a proxy concentration, not a real concentration.

Then if you want to dye 50 grams of leather at 100% WOL then you would use 50ml of your dye since the dye is 1gm/ml.

Convenient, huh?

3. Walnut does not require a mordant when dyeing leather.

4. Roche alum (i.e., potassium alum, not plain alum) is the best mordant for leather. Use a weight of dry Roche Alum at 10% to 20% WOL. Crush the Roche Alum to powder and dissolve with just enough hot tap water to cover the leather, then soak the leather for a minimum of 2 hours. Then you can let the leather dry and dye later, or proceed right to dyeing.

5. Adding chalk (real calcium carbonate, CaCO3) really brightens the color when dyeing with of Madder root extract.

6. Vinagroon takes days to get a rich black color - like 3 to 4 days minimum. Neutralize the leather with a soak in bicarb when you're done soaking it.

7. Here are my final dye results:

[Harry Marinakis]

Here is a dye test using a dye extract from Harbor Freight walnut blast media, neutralized with baking soda to pH=7

Even when used at >1,000% WOL, it's a really weak brown dye. Mordants don't seem to have made a difference in the color - and I read today that you don't need a mordant when using walnut.

[Harry Marinakis]

This a dye extract from Madder root, with a dash of lye (KOH) and 1/2 tsp of slack lime. I'm guessing it was dyed at about 100% WOL. Alum was a pretty good mordant - but then so was water! The color isn't very exciting.

[Harry Marinakis]

This is the same dye as above, at 100% WOL, except that I added a mere 1/4 tsp of chalk to brighten the color. Three things to note here:

1. Alum was the clear winner as a mordant.
2. The leather swatch without a mordant (water) clearly shows that a mordant is necessary with Madder root.
3. Chalk REALLY brightens the color! Imagine if I had added 1 tsp. of chalk!

[Harry Marinakis]

This a vinagroon at 48 hours. It actually looked black today in the solution, but it's really just a dark, dark, dark blue-purple. I am guessing that soaking it for 3-4 days would really make it black. But that's another experiment.

Alum as a mordant seems to have edged out Cream of Tartar.

[RandallMoffett]

Hey these at turning out great now Harry. Well done! That is a great deal of patience and perseverance at work! Great job!

It is amazing to see how vibrant as well as dark some of those colors you have are!

RPM

[Harry Marinakis]

Continuing my journey into medieval leather dyes.....

Vinagroon is supposed to dye leather black.

It is easily made by dissolving degreased steel wool in vinegar. it takes about a week for the steel wool to dissolve. The resulting solution is grey.

You won't be able to dye anything black, though. The color comes out a very dark steely blue (see above posts). I have read people's blogs on the Internet where they soaked leather in vinagroon for a week or two, but never got black.

[Harry Marinakis]

HOWEVER - if you open the vinagroon to air for another week and allow the solution to oxidize to a rust color - THEN you have mature vinagroon that will dye leather a saturated black within a matter of hours.

Here I soaked leather in vinagroon for 2, 4, 6, and 8 days. The leather was as black after 2 days as 8 days.

You can paint vinagroon onto leather - but even after multiple applications all you get is the steely blue. In order to get black black you have to soak the leather in mature vinagroon for several hours.

[Harry Marinakis]

Weld flowers are used to dye fibers a brilliant yellow color. It doesn't work on leather, through, you get a putty color and that's it.

Here the control swatch is undyed leather.

Weld? Forgetaboutit.

[Harry Marinakis]

Brazilwood (Guilandina echinata) is a hardwood tree in Brazil that is famous for a medieval dye called verzino. The wood is bright yellow. The trees were over-harvested for dye and musical instruments, so now the species is endangered and international trade is prohibited. You can still find some sources in the USA that have old stock of Brazilwood that they obtained before the trade restrictions were imposed.

So I bought a 2" x 2" x 28" turning block of Brazilwood, shaved it down, and boiled it to get an extract.

The extract is a brownish-orange color and has a pH = 6 with my tap water. But the color changes with pH.

[Harry Marinakis]

I dyed several pieces of leather using Brazilwood extract, adjusting the pH of the dye bath from pH=5 to pH=9 using vinegar, baking soda, and lye.

I found that when I used the mordant roche alum, and took the wet leather right from the mordant pot to the dye pot, it dropped the pH of the dye pot by 1.

The pH listed below is the pH of the dye bath BEFORE I put the mordanted leather swatch into the dye.

[Harry Marinakis]

I've been working on more dye experiments with Madder root. The results are quite variable and not reproducible. Even the source of the Madder root makes a huge difference in the color. Powdered root seems to be working better than crushed root. Obviously, fresh root would be best, but Madder has to grow for 5 years before the root can be harvested for dye.

Given the beautiful, satured reds that I am getting with Brazilwood, I think I am going to abandon further experimentation with Madder root and leather. Madder may work great with fiber, but leather is another story.

[Harry Marinakis]

I have tried the mordants roche alum (not plain alum), cream of tartar and tin. So far, roche alum seems to work the best for leather, at 25% WOL (weight of leather). Weigh the leather to be dyed, then weigh out roche alum at 25% of the weight of leather. Dissolve the roche alum in just enough hot water to dissolve it. Soak the leather for 4 hours in the roche alum solution before dyeing. If you've got a big piece of leather that requires a lot more water to cover it (dilution), then go with roche alum @ 50% WOL.

You do not need a mordant with walnuts and vinagroon.

Still to come - experiments in dyeing leather with Old Fustic (Argentine Osage Orange), New Fustic (North American Osage Orange), indigo, and maybe some lichens.

This autumn, when the walnuts and berries ripen, I will delve into brown and green leather dyes.

So far I have learned that natural dyes are funky, and it's difficult to get reproducible results. I have repeated these experiments a few times, using the same procedures, and got different results every time. Obviously, I am unwittingly doing something different each time. Moral of the story is: If you want reproducible results, then write down your recipe as you work through it. No detail is too small - mordants, temperatures, pH, weighs, volumes, etc. Then follow your procedure exactly if you want to reproduce prior results.

The leather itself seems to have a big effect on the outcomes, too. I have been using undyed veg-tan tooling leather from Tandy and other merchants. Different leathers, different results.

So far I have been working mostly with raw dye extracts, and haven't even been using medieval recipes that call for multiple other ingredients. Once I figure out how the raw extracts behave, then I'll start trying some medieval dye recipes.

Stay tuned for more.