What's Actually in Stencil Gel and Transfer Paper?
After I lay a stencil, the needles work through the material it leaves on the skin. I want to know how much of that residue stays on the surface and how much enters the punctures.
A stencil goes on intact skin, then gets punctured a few thousand times a minute. Some of that residue enters the punctures, some mixes with ink, some wipes away. Which of those happens, and in what amount, has not been measured for any product I can find.
I formulate stencil products, so I have a personal reason to ask. Ingredient lists and safety data sheets give us a starting point; they don't measure what happens during tattooing.
What is in the gel
VitaliTree's Stencil Gel ingredient list includes AMP-Acrylates/Allyl Methacrylate Copolymer and carbomer. Both are synthetic polymers, notwithstanding the product's petroleum-free description. No concentrations or particle sizes are given.
An older Stencil Stuff Gel safety data sheet dated 12-04-18 lists carbomer at 0.30%, "Poliquaternium55" at 1.20%, propylene glycol at 15% and quaternium-15 at 0.10%, with Concentrated Aloe Corporation as manufacturer. I have reproduced the spelling from the sheet. It is an old document and the current formula needs confirming.
A clear gel can still be a polymer network
This is the part that surprises people. Carbomer swells in water without dissolving. EFSA's assessment of carbomer as a food additive describes crosslinked polyacrylic-acid polymers forming hydrogels exactly that way. So a gel can look perfectly clear and still contain a swollen polymer network throughout.
A swollen gel, a dried film and a detached fragment are three different physical states. Calling any of them a microplastic requires measuring the actual material's size, solubility and state. Drying a sample for microscopy changes it, which is why the wet gel has to be examined too.
EFSA found no evidence of systemic availability or biotransformation in the animal data and no genotoxicity concern in the standard tests. Those are useful findings about oral exposure. They don't evaluate stencil residue during tattooing.
Carbomer has been studied for other uses. What those results don't answer is how a stencil formula behaves when it is left on skin that is then repeatedly punctured.
What comes off the paper
Spirit's July 2018 safety data sheet for Classic Stencil lists C.I. Basic Violet 3, crystal violet, CAS 548-62-9, at 10 to 30%, in a waxy coating on paper or film. That percentage describes the product mixture, not what transfers to a client, and the sheet does not disclose the full coating formula.
How these coatings get made is documented elsewhere. A 1977 infrared-transfer patent describes crystal violet and methyl violet carried in mineral oil, castor oil and waxes. That explains the general construction; it cannot establish any modern tattoo paper's recipe. Dye and wax are not automatically microplastics.
Inkjet stencils work differently again. A tattoo-transfer patent describes methyl violet in isopropyl alcohol, glycerin and water printed onto a flexible sheet. An example formulation, not a universal ingredient list. Paper coatings and liquid stencil inks need separate testing.
The question that matters: what does the gel pull off the paper and leave on skin? Dissolved dye, coating ingredients, gel polymer, loose particles. A purple mark does not distinguish between them, and it says nothing about how deep any of it goes.
What reaches the punctured skin
No peer-reviewed study has measured the implantation and retention of chemically identified plastic particles from stencil gels. That is the gap.
The amount spread on skin is not the implanted dose. A useful experiment would remove and measure the surface residue first, then separately analyze what stayed below the surface.
Known irritants, in proportion
The reaction data needs its exposure conditions attached. An ingredient name alone isn't enough to tell us what a stencil product will do.
In a study of 23,359 patients referred for patch testing, 3.5% reacted to propylene glycol and the face was the most commonly affected site among those positive only to it. That was a selected referral population rather than a survey of tattoo clients. It also used a 30% test preparation, and detection is strongly concentration-dependent: later work found 2.19% positive at 30% aqueous, rising to 7.82% at 100%. The Stencil Stuff sheet lists propylene glycol at 15%, so the 3.5% figure is from a stronger exposure than that product carries. Propylene glycol also behaves as both a weak sensitiser and an irritant, which confounds patch testing, and it is not a plastic.
Quaternium-15 releases formaldehyde and is an established contact allergen per the SCCS 2011 opinion. Two things that opinion also says, and that fairness requires including. It is permitted as a cosmetic preservative up to 0.2%, and the gel sheet lists 0.10% — half the limit, not over it. And the SCCS concluded quaternium-15 has no in vivo genotoxic potential. The concern is sensitisation, nothing broader. Note too that it is a different ingredient from polyquaternium-55, despite the similar name.
As for the polymers themselves, a 2023 study found oxidative stress, altered Wnt signalling and cytoskeletal disruption in primary mouse skin cells exposed to polystyrene particles between 0.2 and 6 micrometers. Direct cytotoxic effects were less apparent: the particles changed how cells behaved more than they killed them. Those results belong to polystyrene, and they cannot predict what carbomer or an acrylate copolymer does at an unknown tattoo dose.
Both the particles and the soluble ingredients need attention, and they need different tests. Preservatives and residual monomers call for chemical analysis; polymer fragments call for particle analysis. A long track record of using these products on intact skin tells you nothing about what happens when the same material meets an open wound.
The DMSO question
I helped develop the original Beastmode stencil-gel recipe. As I remember it, the recipe still needed modification when it was sold. It used 99% USP dimethyl sulfoxide as the starting material with Carbopol, grade 960 or 980, and depending on the grade a small amount of triethanolamine. Proportions could shift with raw-material cost.
That is my recollection of a historical recipe, not a verified specification. The 99% refers to the purity of the DMSO going in. Without batch quantities it is not the finished gel's concentration, and it establishes nothing about what any current product contains. I could not locate a publicly accessible SDS confirming present DMSO content for any retail version.
Why it matters: DMSO increases the skin's permeability to certain chemicals. A mouse-skin study measured its concentration-dependent effect on vidarabine transport, and FDA's PENNSAID review discusses it as a penetration-enhancing carrier. Neither tested a stencil product.
The following studies help explain DMSO's effect on skin. They tested intact skin, so they don't establish a dose or a safe use for tattooing.
A 1977 study in the AIChE Journal found that when a DMSO concentration gradient is driven across human skin, permeability to a model drug rose by one to two orders of magnitude. Microscopy showed marked swelling, distortion and intercellular delamination of the stratum corneum, only partially reversible after the skin was fully extracted with water. A gel sitting on the surface is precisely how you create such a gradient.
The 1976 paper discussed below also looked at survival. Skin incubated in medium containing DMSO survived only at very low concentrations, with degeneration after a few days at 4.5% and much sooner above that. That is a low threshold for a solvent some gels may carry in quantity.
And the RIMSO-50 label carries a warning that gets overlooked: DMSO can liberate histamine, and hypersensitivity reactions have been reported with topical administration. That is a regulator flagging a skin reaction to DMSO itself, not to whatever it is carrying.
How much actually crosses depends on the chemical, the formula, the DMSO concentration, exposure time and skin condition. And moving a dissolved substance more easily does not mean whole polymer networks or surface contaminants follow it. Material entering skin is also not the same as material reaching the bloodstream.
For scale, PENNSAID 1.5% contains DMSO at 45.5% by weight. Its label instructs patients not to apply it to open skin wounds, infections or inflammation, and gives the reason: doing so may affect absorption and reduce tolerability. It also tells patients to wait until the area is completely dry before applying anything else topically, which the labelling notes usually takes about ten minutes. That is a prescription product containing diclofenac, so none of it sets a safe concentration or waiting time for tattooing. What it does show is that a regulator thought the combination of this solvent system and broken skin was worth writing instructions about.
Cleaning over a treated surface
Tattooing means repeated cleaning, usually after the needles have already opened the skin. If DMSO is still on the surface, or its barrier effect is still active, that changes exposure to the cleanser and to whatever stencil material is left.
A 1976 study of human skin found DMSO increased the passage of labeled water, with the effect depending on concentration and exposure time, and the barrier recovering only partly after the solvent was removed. Partly. Looking dry does not mean permeability has returned to normal, and nobody has established how long recovery takes in a tattoo client.
Green soap varies by formula and dilution. Dynarex describes its concentrate as 30% alcohol requiring dilution, which is not the concentration you actually apply. Any experiment would need to record the specific cleanser, mixture and timing. No direct study of this combination exists.
I also remember something from using the original gel. I remember an intense putrid garlic or onion smell filling the room when we used the original gel. Smell measures nothing on its own. But the RIMSO-50 label describes how DMSO is metabolised to dimethyl sulfide, which is eliminated through the breath and skin and is responsible for the characteristic garlic-like odour, lingering up to 72 hours. What I was smelling has a name and a pathway. It does not tell me the concentration, and it does not tell me what crossed anyone's skin.
How this should be tested
Start with several brands and lots. Analyze the paper coating, the gel and the transferred stencil separately, including samples after drying and rewetting. Measure soluble violet dyes, polymer particles, residual monomers and preservatives. Run controls that would reveal contamination from the packaging or the analysis itself.
Then compare needle-only, ink-only, gel-only, paper-only and combined exposures in donated skin or a reconstructed human skin model, under an approved protocol. Follow normal application, drying and wiping. Collect the stencil, the wipes and the rinse fluid, and keep surface residue separate from what stayed in tissue.
That design is not hypothetical. A 2025 study tattooed a reconstructed human skin model and tracked cytotoxicity, cytokine release and gene expression over seven days. Tattooing alone produced a strong inflammatory response that subsided around day four, and introducing ink increased the cytotoxic effect on top of it. In other words, the model already separates needle injury from what is being injected. Nobody has pointed it at stencil gel.
For a DMSO-containing gel specifically, start with what it extracts from the paper, then compare uptake through intact versus punctured skin against a DMSO-free formula. Carbopol grade and solvent mixture matter here too: a DMSO-rich gel has a different structure from a water-based carbomer gel.
What I would ask a stencil supplier
I would ask for a full ingredient list with concentrations and a current, dated SDS for the product being shipped. If it contains DMSO or another penetration enhancer, I want the concentration stated. I'd also ask whether the finished product has been tested under the conditions of tattooing, including contact with punctured skin.
None of this means stencil products are dangerous. Every ingredient above sits within its permitted cosmetic limits where limits exist, and several have been evaluated thoroughly for other routes. It means the questions have not been asked for this route, and they are answerable. The same gaps exist across tattoo supplies generally, which I cover in do tattoo supplies shed plastic? For what happens when a numbing agent goes on top of all this, see numbing cream and tattooing.
Sources
Warshaw et al. (2009), positive patch-test reactions to propylene glycol, Dermatitis 20(1):14-20
SCCS (2011), opinion on quaternium-15, SCCS/1344/10
FDA (2009), PENNSAID NDA 020947 pharmacology and toxicology review
PENNSAID 1.5% prescribing information, DailyMed
RIMSO-50 prescribing information, DailyMed
VitaliTree, Stencil Gel ingredient list
Concentrated Aloe Corporation, Stencil Stuff Gel SS-1234 safety data sheet
Colonial Carbon Company (2018), Spirit Classic Stencil safety data sheet
US4049843A (1977), image transfer layers for infrared transfer processes
US8545613B2 (2013), tattoo transfer pattern printed by an ink jet printer
Dynarex, Green Soap product description
This article reviews published research, product documents and my own observations. Some sources were available only as abstracts. No original measurements are reported here, and nothing above is medical advice.
For tattoo work in Arlington, Texas, visit the booking page.
