[Otterly Foolish]

I have been in the tattoo business for 20+ years and have mixed a lot of my own ink over the years using the methods taught to me by my mentors and other seniors in my trade. I have never had a problem and am relatively content with what I am using but my curiosity is getting the better of me these days and I want to understand more about what makes certain things work better than others. I am working with non-toxic and mostly organic pigments(PR 120, PR 170, PO 16, PY 74, PG 7, PB 15, PV23) except for titanium dioxide(PW 6) and carbon black(PBlk 7). In my list of other ingredients I have propylene glycol, glycerin, witch hazel, isopropyl alcohol and vodka for the ethyl alcohol. These are not all used in each color, some colors seem to work better with some ingredients and that is what I want to understand better. I also read some MSDS sheets on inks that I have purchased and see things like polyethylene glycol 600, polymers,  acrylic resin, wetting agent, surfactant and dispersing agent. I would like to try and understand what affects these have on the different mixtures and if they are even necessary because I have been getting by without them for years. Or am I missing something that might add to my artwork? The people making these inks on a large scale surely must know more than I do.

Can you guys recommend some reading or maybe give me some basic ideas on what to be looking for to expand my knowledge on the subject. I vaguely remember high school chemistry but I do know that I excelled in that class so I am hoping to be able to pick up on this stuff fairly easily. So do you think you could help me understand this at least somewhat more than I do?

Thanks

[enahs]

You are looking for some very specific information pulled out of Chemistry. So, other then I think it is great and you should read a general chemistry book, I do not think it would help you very much for what you are looking for, in truth.

Looking up some ink chemistry books, well, they are ridiculously expensive (because so few people buy them). Like, I was finding $200 for used versions! So I would recommend you find the website of your local library system and search for the term "chemistry ink" and see if any books come up, and go check them out for free. These will not focus on tattoo inks but inks in general, but it would be a great start.

I am worried they might all start off a little to advanced and why I would try library first because of their price.


It is funny you posted this, since I just got back from getting my first tattoo! Like literally 2 hours ago!

[Honclbrif]

Before I start I should let you know that I am not any sort of official 'ink chemist', but I do have some interest in things which have color. I also really like it when people express an interest in chemistry. Especially when it is chemistry that touches their daily lives. Keep that curiosity alive. With all that in mind, I''ll give you my best thoughts. I hope this may act as a starting point from which you can more thoroughly research things; do not take this as absolute truth.

"polyethylene glycol 600, polymers,  acrylic resin, wetting agent, surfactant and dispersing agent"

Polyethylene glycol (PEG, also sometimes called polyethylene oxide or PEO) and other misc polymers are probably acting as thickening agents. PEG has the interesting property of being almost completely biologically neutral. For some reason, the body just tends to ignore it and it dissolves and gets excreted without much fuss. Wetting agents probably affect how the ink adheres to the needle, and dispersing agents probably affect how the pigments are dispersed throughout the ink (prevents settling while the ink sits on a shelf).

As for how they affect color, there's a little science there and a little voodoo.

I'm assuming most tattoo inks are probably pigments and not dyes. Pigments are very small colored solid particles. They can be completely inorganic (like titanium dioxide or iron), or organic. I suspect the acrylic resin may be microscopic chunks of acrylic plastic with dyes embedded in it. The effects you see are probably related to how well the pigment particles are dispersed throughout the skin (very fine and even, or coarse and clumpy). This in turn is probably related to how well they are dispersed throughout the ink, and how well the ink is dispersed on the needle. Various additives affect these things.

That's the science part. The voodoo comes in after the stuff is actually in the skin. The body has its own crazy ideas about how it wants to treat this stuff: break it down, move it around, or ignore it.

Depending on how scientific you want to be about this stuff, you may want to see if you can find someone who will let you use a microscope you can fit a hand or arm under (a powerful loupe might work too but magnifiers aren't really my thing). If its powerful enough you may be able to get a better look at how the particles are distributed (though they'll still probably look like smoke, even under high magnification) and how that affects color. From there you may be able to determine how different additives affect things. However, this is also probably going to take some pretty chill volunteers.

Anyway, good luck in figuring out how to build a better tattoo ink and how to further your craft.

[Otterly Foolish]

enahs,

Thank you for your reply and congratulations on getting your first ink. I am not so sure about the coincidence, I am one of those guys that believes everything happens for a reason and I have a tendency to time most things that I do mysteriously well. I am not afraid to spend a little money in order t learn more but the guidance in the right direction can be priceless. I will definitely check out my local libraries for ink chemistry books. You mentioned that they might be a little to advanced so what would you recommend as prerequisite reading as a primer?

Thanks

[Otterly Foolish]

honclbrif,

Thank you for your reply, I appreciate you help. You are correct in your assumption that most tattoo inks are pigments. Dyes would simply stain cells and generally heal out of the skin with time. Well placed tattoo pigment is just below the regenerating layers of the epidermis but not too deep in the permanent layers.

Having the right pigments is the easy part for me. The carrier is only to assist in getting the pigments into the skin and then it should heal out of the body leaving little or nothing behind other than the pigment. The variables are in the carrier and you want that to do exactly what you mentioned, disperse the pigment into the solution and allow adhesion to the needles. The only one I have had an issue with in the past is the dispersing part so I may have to look into a good/safe dispersing agent. There are a few colors that have a tendency to separate in the bottle after sitting for a period of time. They can easily be remixed with a little agitation but I would prefer if they would stay evenly dispersed so that my results in the skin would be more uniform.

I am curious if the the PEG would help with the dispersing of the pigments. I am assuming it has a higher viscosity if it is used as a thickening agent. If not then it may be some companies attempt to compensate for using less pigment in their inks.

I may just need to locate a strong microscope and inspect the ink in my arms like you said. I am not sure where to start looking but I will keep my eyes open for sure. There are always and abundance of volunteers if you are willing to do free work on them. My only concern is that I find safe chemicals to use in my experiments and I would certainly be willing to use them on myself first for peace of mind.

Thanks

[enahs]

Do not be offend when I say this as a first initial primer; as it is what I have my college level students do unofficially.

The Cartoon Guide to Chemistry. http://www.amazon.com/Cartoon-Guide-Chemistry-Larry-Gonick/dp/0060936770/ref=sr_1_1?ie=UTF8&qid=1307899078&sr=8-1
It is cheap, simple and quick to read while not being boring.

I always tell my students "it is easier to learn something if you already know it". Which sounds stupid and confusing at first; but if you think about it, it makes a lot of sense. Build up slowly on the information you already know.

Another GREAT book for non science people to get introduced into Chemistry, and VERY interesting, is called Caveman Chemistry. It does talk a little about some dyes and such, but its very cool and interesting book.
http://www.amazon.com/Caveman-Chemistry-Projects-Creation-Production/dp/1581125666/ref=sr_1_1?s=books&ie=UTF8&qid=1307899200&sr=1-1

A cheap more textbook like Chemistry would be a Schaums Outline to College Chemistry http://www.amazon.com/Schaums-Outline-College-Chemistry-Outlines/dp/0071635300/ref=sr_1_1?s=books&ie=UTF8&qid=1307899278&sr=1-1

Truthfully, if I was allowed to pick the books for college freshman general chemistry 1 & 2, I would use those three books. Cheap, you learn stuff you already know (building up), cheap! (The whole textbook politics and industry is so corrupt and annoying...

[enahs]

Ohh, and one other thing. Maybe you have heard of doing something similar; but I have no doubt tattoo ink company's always test out their new ink on a pig first. If you do make your own ink one day, I would try it on a pig first. Then cut off the skin with the ink and have a big ole BBQ or laua!

[Otterly Foolish]

enahs,

Thanks again, I just ordered all three from Amazon. I actually consider myself to be a science guy, more on the engineering and physics though. I just happen to be artistic also and it has provided well for me. I am a lucky guy to be somewhat ambidextrous and able to use both halves of the brain fairly well. I do need to ask a new question now and that is, how do you get the pig to sit still? LOL

Thanks

[fledarmus]

Do some searching on surfactants, which I think is what you are really looking for. "Surfactant" is a word made up from "surface active agent" and refers to compounds which change the surface properties of a material. Dispersing agents are long molecules that have one end that interacts with the pigment particles and the other end interacting with your solvent - since the solvent would much prefer to interact with itself than with the pigment, the pigment particles will usually end up on the bottom of your bottle with no dispersing agent. Emulsifiers are similar molecules but stabilize mixtures of immiscible liquids, like oil and water. A layer of surfactant molecules can surround a tiny droplet of oil, forming a micelle which can be dispersed through the water rather than simply floating to the top. Wetting agents increase the interaction between water and surrounding solids, essentially lowering the surface tension of the water. This makes it easier for the water to flow onto a brush or through thin needles. Thickeners are very long molecules which interact both with the solvent and with each other, forming tenous three-dimensional networks throughout the solution which are strong enough to thicken the solution, but tenous enough to move when they are subjected to physical forces like stirring or pouring.

Dispersants, emulsifiers, wetting agents, and thickeners are all examples of surfactants.

Hope this helps

[fledarmus]

Ahh - one other point, you are looking only at drug-grade materials to be used in injecting tattoo inks, right?

[Otterly Foolish]

fledarmus,

Thank you for your input. I really appreciate the visual pictures that you painted with your descriptions of the different surfactants. You are correct, I am only looking at drug grade/FDA approved ingredients. Is it common for inks to have multiple surfactants, each to achieve a different effect?

I just bought a small digital microscope that is capable of up to 2000x for experimenting with this. Do you think I will I be able to see the interactions between the different ingredients with this? If so what would I be looking for?

Thanks

[fledarmus]

I'm afraid the structures you would be looking for are far smaller than you would see with any optical microscope. I don't know what sort of pigments you use in tattoo inks, but the pigment particles themselves are probably at the very limit of what you could see at 2000x, and the interactions between molecules of surfactant and solvent or surfactant and particles or surfaces is many orders of magnitude smaller. Depending on the type of emulsion, it is possible that you would see micelles formed in an emulsion.

You will need to use much broader physical property measurements as a proxy for visualizing molecular interactions. For your part, it is these broader physical properties that you are trying to control anyway, so you might as well measure them. The thickness of the solution can be measured as viscosity, and an easy way to do this at home is with a rolling-ball viscometer. Take a long glass tube with a rack that will hold it at an angle, fill it with the solution you are testing, and roll a ball-bearing down the tube through the liquid. Measure the time it takes to pass between two marks on the tube. The mathematics underlying the system are fairly complicated (see http://deepblue.lib.umich.edu/bitstream/2027.42/6541/5/bac8244.0001.001.pdf if you are interested), but all you really want to know is whether your experimental solution is as thick or thin as your favorite tattoo ink. Measure your ideal standard first, then thicken up your test solutions until the ball-bearing takes the same amount of time to go through them as it did through your standard.

The emulsifiers can be tested using stability tests. Simply mix up your solution with the emulsifier you are testing and let it stand. Graduated cylinders that can be capped are ideal for the purpose. If the emulsion separates you should be able to see the separation, and the graduations on the cylinder will allow you to measure the amount of emulsion remaining.

As for wettability, I'm not sure exactly how you would test that. There could be two uses for a wetting agent for tattoo inks - 1) to improve the wetting of the pigment particles by the solvent, or 2) to improve the wetting of the tattooing equipment by the solvent. Some of the testing possibilities might include the measurement of the diameter of a drop of liquid of known volume on a test surface such as a plate of glass or polished metal (better wetting solutions of the same viscosity would spread out further?), or dropping a drop of a test solution onto a slanted test surface (better wetting solutions of the same viscosity should slide faster down the surface?), or dipping a piece of filter paper into the solution for a standard period of time (better wetting solutions should travel upwards faster?) These are just my guesses - you could probably find others doing a net search.

Best of luck