LakeOtter

Thanks, I appreciate it.... I did mean to mention why I'm working with the aniline powder, versus other options, when there are options that don't have the same concerns: It's because I'm super strapped, can't really go buy anything new right now (esp. various colors) and already have gobs of red, yellow, blue, and green, pure aniline dye powder I bought from Bingham's for archery bow wood, and I'm loving the colors. I discovered I already had at least a year's worth of any color I wanted, using those (including any brown hue or mottled combo thereof). It's an interesting development finding out that: Professional aniline leather does not appear to be made with water-based aniline dyes like bookbinders use, because they repeatedly refer to the "oils in the aniline dyes" soaking into the leather with the soluble pigment. I've noticed aniline dye, aside from being soluble in water, is also soluble in pure alcohol. As long as there's no water in the alcohol, pure alcohol mixes with oils. I'm thinking something like this is how they formulate oil-based aniline dyes (or solvent-based aniline with oils in it). Dissolve it in pure solvent then add to oils. I might be able to try that, too, unless my red dye (which was already made up by me a long time ago) contains any water. If I used pure denatured alcohol like it smells, then I can try making the oily kind of aniline dye which I'm betting won't leech out with water like it can with water-based aniline dye (and why bookbinders buy expensive Hewitt Dye-Fix "Methanamine"). We also have to mitigate the oils we use on bookcovers, too, but I do use them. I'm sure even if I use the water-based aniline dye recipe that by buffing the surface and using a oil/wax conditioner well, there won't be any real problem. I was just really curious why bookbinders insist on using expensive methanamine fixative on leather they aniline dye when no other craft seems to. It's probably because (besides the whole archival thing) they are using water-based aniline dye whereas those who professionally make aniline leather for other uses use a solvent-and-oil based aniline recipe that is less susceptible to water getting on it and causing ruboff. I know waxing and oiling repels water... but I can really go to town on pro aniline leather and water won't make it leech (even though they tell me they use no fixative). Instead, if I hose it down with oil (which they say never to do with aniline leather) maybe it would, since it was formulated that way, but it never rains oil on the side of a car seat. I really appreciate the replies, it furthers my suspicion that it's not a big concern, and I learned about a new colorfast dye for the future and I'm really curious about finding out it Retayne for fabric is chemically anything like the expensive Hewitt Dye-Fix that is the status quo for book binders and conservators.

Wow I did also just find out that there is a total difference in aniline dye formulas. At a tannery (or place where they get the dye) the aniline powder appears to be liquified with solvent that will mix with oils, not water, because it says there are oils in the dye (whereas bookbinders and wood workers use water and sometimes alcohol). If you put oil in water-based aniline dyes like bookbinders make, it would just float on top or emulsify and make a mess. This explains why you can use oily conditioners with neatsfoot and lanolin on new book leather dyed with water-based aniline dye, whereas everyone says "never apply oil" to "aniline leather" like used for auto upholstery. I'm assuming oils would interfere with oil-bearing aniline dye, whereas oils protect water-based aniline dye. This also explains why spilling water on "aniline leather" won't make it leech aniline dye out no matter how much you soak it. They haven't used a methyl-anything fixative... they've made it basically oil-based, instead. At least so it seems, with multiple sources saying "oils soak through the leather along with the soluble pigment" when making "aniline leather". And no one sits there soaking their car seat in oil until a little dye leeches out. But they do accidentally get rained on. It's all making sense now.

Thanks I really appreciate it. I know Hewitt "Dye-Fix" works but its expensive. I can understand using it on a priceless museum piece with velum documents pressed up against it... I will likely buff to eliminate rub-off as you said. That will keep from most rub off but theoretically if the object got really wet and was no longer repelling water 100% from oils/waxes it could dribble out. I'm not going worry about it a lot but: Wow! Thanks for mentioning "Retayne", though! I'll be comparing it to Hewitt's "Dye-Fix" and maybe ask the company about leather. I was able to find that Retayne's ingredient is a trade secret but the family of chemical is a "cationic methylene guanidine". Dye-Fix is "Methanamine" or "N-methyl-, polymer with 2-(chloromethyl)oxirane" ...sounds suspiciously similar. But Retayne is wayyy more affordable. Just no telling if it causes the leather to break down faster, not being washed out (unless I could confirm it's the same stuff, since Dye-Fix is archival and museum conservator approved. That's also cool about the burnishing formula. It definitely seems that things that polymerize are known to lock the aniline into a bonded state where it can't leech. Thanks again

Hello and thanks for your time. I have leather experience, and aniline dying wood experience, but not much aniline dye on leather experience. You can buy pure aniline dye powder and mix it with water, alcohol, or a combination, but I have a feeling professional "aniline leather" has had some fixative or process used so, for example, auto upholstery aniline dye never, ever rubs off on clothing. Something more than just a coat of oil/wax/UV blocker over the top of it. Something to make the aniline dye never reactivate with moisture that gets past a mere topcoat. That is, unless veg tan leather simply bonds to it, alone, adequately so it can't reactivate like aniline dye dried up on the bottom of a jar. I was wondering if any of you have ever dyed leather with aniline dye and then either: 1) used a fixative so moisture doesn't re-activate the normally, very water soluble dye or 2) ever had any problem with the leather getting wet and rubbing off on someone's clothes. As soon as you enter the bookbinding realm, they apply Hewitt "Dye-Fix" after applying aniline dye (that they prepared from powder and water) to lock it in so it doesn't reactivate with a spill or a dash through the rain. The MSDS reveals is some strange chemical "Methanamine" or "N-methyl-, polymer with 2-(chloromethyl)oxirane". It is supposed to chemically lock the dye itself from reactivating, not just topcoat it like an oil and wax product. Since I have never heard of "aniline leather" staining anyone's cloths from a car seat that got damp (the only reason they recommend conditioners is so it doesn't fade) I figured professional tanneries treat it with a fixative. But some auto upholstery places even sell DIY aniline dyes, but no fixative and, when asked, they were unaware of any fixative in the product and said "Hewitt's dye must not be real aniline" which is simply not true. You can buy powdered aniline dyes for leather and wood and other things and they are real aniline dyes, period. It does make sense that, unless a chemical bond is 100% formed with the subject getting dyed, it could moisten and reactivate and ruin someone's shirt. That is... unless the chemical nature of vegetable tanned leather already forms an adequate bond. For this I'm about to do some tests. I don't want to buy expensive fixative (which is, seemingly, only even known about in the bookbinding niche) if all the career leather guys know it's totally unnecessary with veg tan leather. Sure I'm going to rub on oil and wax but I don't like the thought of it being a ticking time bomb to rub off and expose dye that can stain clothes). I know aniline is more a solution and not so much a suspension of pigment that lies on top of surfaces but fact: you can, nonetheless, allow it to dry to the sides of a glass jar and wind up with re-usable dye powder. So there's got to be a bond formed to something before it won't transfer to something else. If tests show it just isn'ty an issue, this means aniline dye tends to form its own bond to veg tan leather without "Dye-Fix"... if it rubs off badly with a mist of water, though, it must mean tanneries use a fixative or process of some sort beyond just oil and wax. One of the two must be true, I just don't know which. If you have any true insight about this, I'd really like to hear your experiences or knowledge, thanks. Jeff in Odessa FL