Which Test Uses Color Change to Reveal Oil Based Paints

Aside from baking and clearcoats, the most common questions I am asked have to do with painting polymer clay. Everyone wants to know why they're getting bad results. They want to know if they should "seal" the paint. But the biggest question is, "What paint should I use to paint polymer clay?" It's a really hard question to answer in a quick comment, so for a long time I've just said, "It depends." Depends on what? Well…it's a long story, and after you take all of it into consideration, you may want to rethink using paints on your polymer clay project. Here goes.

(BTW, looking for what happens when you mix paint INTO polymer clay? You might like this article.)

Problems with Painting on Polymer Clay

You'd think that painting on polymer clay would be simple, right? Just like painting your nails or a wall. Just dab it on and be done, right? Oh boy. If only. Here are some common problems that people run into when they try it.

Stickiness

Most paints are designed to work well on paper or wood. Most online information about painting assumes you'll be using paper or wood as a substrate (base). But painting on polymer clay is a whole different game.

Polymer clay is a plasticized vinyl that can have a chemical reaction with the products used on it. If the paint contains plastic (and most acrylic paints do), the plasticizer that makes the polymer clay flexible can also soften the paint, making it sticky. Different brands of polymer clay and different brands of paint can have completely different interactions. A paint that works well for Sculpey III might be a sticky mess on Fimo. Always test the paint you want to use on a baked sample of the brand of clay that you want to use. Always. (Did I say always? Yes. Believe me on this.)

By the way, oil-based or water-based is irrelevant. Either type of paint can work well…or not. Test them.

Also, you can sometimes remove sticky paint by using isopropyl alcohol. If it's only a tiny bit sticky, a coat of clay-safe varnish can sometimes cover up the problem and cover the stickiness.

Poor Coverage

Some paints are opaque and will cover a surface with one coat. Other paints are more translucent and you'll see through it, often with obvious brush strokes. Coverage is due to the density of pigment, but pigment is the most expensive part of any paint formulation. In addition, most paints are designed to work well on absorbent materials like paper, wood, and fabric. When applied to polymer clay, less paint is used and therefore there is poorer coverage. Inexpensive craft or hobby paints will often require many coats to give full coverage and this many coats makes a paint gloppy and uneven. Very few brands of acrylic paint give complete, opaque coverage in one coat.

Many inexpensive craft paints have low pigment density and therefore give terrible coverage. It would take many coats of this paint to give a smooth coating.

Peeling, Chipping, Scratching Off

Polymer clay is vinyl plastic and therefore paint can't absorb into the material the way it does with paper, wood, and cloth. It sits on top. And that means that paint on polymer clay is very likely to peel, chip, and scratch off with wear. Some brands of polymer clay will allow better adhesion than others. Generally, paints stick well to Souffle, Sculpey Ultralight, Sculpey III while they tend to stick poorly to Kato Polyclay. Adhesion is always better (with any brand) if you first sand the surface very lightly with high-grit sandpaper (such as 400 or 600).

Paint will often bond better to polymer clay if applied to raw polymer clay and then baked together. Yes, you can easily bake paint onto polymer clay in most cases. It seldom bubbles or burns, but some paints will change color with the heat, especially if they contain a dye.

Can you protect fragile paint by sealing it with a clay-safe varnish? (If you're looking for a good varnish, check out this article.) Yes, it can sometimes work. Varnish can reinforce the thin skin of paint over your polymer creation. But if this only works if the varnish, itself, is strong. Varnishes are susceptible to many of the same issues we're discussing here in regard to paint on polymer. And no varnish will stabilize a paint that is peeling from the polymer. A bond is only as strong as the first layer!

You could use UV or epoxy resin as a protective clearcoat, too. But if you have a solid layer of fragile, peeling paint, resin will only stick to the paint and easily peel off. Here's more about using resin with polymer clay.

I made these beads when testing various metallic acrylic paints. As you can see, the paint scraped off easily. This is very common when we try to paint polymer clay.

Paint Fades over Time

While paints containing pigments are far more color-fast than paints containing dyes, pigments can and do fade in the sun. In fact, that's why we have to paint our houses again and again!

But be aware that it's not uncommon for craft paints to be colored using dyes (Unicorn Spit is an example). Over time (years), the color can appear to fade as the dye diffuses through the body of clay. I've had this happen with beads stored away in a dark box, so I know it's not due to light exposure. Unfortunately, the product label won't reveal the colorant used in a product so you won't always know.

Painting is a Different Skillset

Sculpting is hard enough, but painting requires an entirely different set of skills. Paint selection is only the beginning. You still have to develop the skills required to create the type of finish you want. Many (if not most) newbies struggle with creating the type of neat finish they hope to achieve.

Lack of Consistent Terminology and Brands Worldwide

Things used to be simple. There was one type of paint for specific things. House paint for outdoors. Wall paint for inside your house. Enamel for painting metal things. Nail polish for your nails. Fabric paint. You get the idea. But now paint companies have blurred the lines between categories of products. Enamel no longer means a glossy oil-based paint. It can now be a bottle of water-based acrylic craft paint. So getting info in public forums can be quite perilous. If someone recommends "a good enamel", what do you buy?

In addition to this, terminology and brands differ in various countries. Ask an American what "emulsion" is and they cock their head like a confused puppy. But a Brit will do the same when you tell them to buy "latex paint". (Spoiler….there is no latex in latex paint.) Paint, chemical, and craft companies tend to distribute their products only within a certain country or region, so brand names are far from universal.

All of this means that it can be (as my British husband says) "next to nigh near impossible" to find the products that people recommend in online groups and forums.

Types of Painting on Polymer Clay

There can never be one simple paint to buy because there is not just one type of painting polymer clay. Each type requires a different process, type of paint, application, and strategy. It's just not as simple as slathering some paint on a polymer clay project and being done with it.

Cartoon Style Creations

Wildly popular right now is a type of graphic art sculpture that originally came out of Japanese anime films and has now extended into our movies, our heroes, and our graphic arts. Little chubby characters with big eyes and rounded features are all the rage and they're made with large expanses of plain color. This style requires a paint that has good coverage and can be applied with precision. This style of painting is very unforgiving and it can be the most difficult to accomplish. Many newbies assume these creations are painted, but few are. In fact, it's far easier to use colored polymer clay when making this style, as you'll see here and here. Polymer clay's natural qualities make it perfect for sculpting this style of sculpture. No varnish or sealer is needed, just a strong brand of clay (such as Premo) and your imagination.

This little crab by Jennifer Sorensen of Wishing Well Workshop is made from colored polymer clay. He would not look so smooth if he had been painted. Notice, however, that the blacks of his eyes are painted. There's no reason you can't combine painted accents on unpainted polymer! You can buy this little guy here, btw.

Layers of Color

Just like traditional oil painting, many sculptures are painted with many layers of translucent paint that build up to create a rich dimensional effect. This also requires a lot of skill but can be more forgiving than the flat cartoon style of painting. Be aware that this type of paint effect requires many thin layers and can take a long time to create. While any type of paint can be used, artist's oil paints are a favorite. This type of surface can sometimes be created with layers of colored liquid clay, so don't always assume an item that you see has been painted with paint.

This cute mushroom by Destiny Johnson of Critters Haven uses layers of paint that have been built up to give shading, dimension, and visual texture.

Antiquing

Antiques are often naturally lighter on the worn areas and darker in the areas where dirt and oils collect, right? That's why the term "antiquing" is given to the practice of applying a dark-colored paint into the crevices and recesses of a textured item. This practice gives an item richness (and makes it look less cartoon-like) and so is often used to make a polymer clay piece feel more substantial and aged. This is the easiest way to use paint with polymer clay. Just rub in the paint and remove the excess with a paper towel. Because this is an irregular process, there's no much skill or neatness required. And the paint is protected in the low areas of the item, so there are generally no worries about the color being scratched off. Just about any dark paint can be used, from artist's oils to acrylics.

Here is the before and after of a dragon eye that Dawn Keener antiqued with brown paint. She also added a few gold accents.

Here's another example of antiquing by Lynn Parker Gill.

Highlighting

The opposite of antiquing, highlighting is where a light-colored paint (often a metallic gilding paste) is used to accent the raised areas of a textured item. This accentuates the texture, making it more visible, and giving a lighter or more decorated appearance to a project. Like antiquing, this an easy technique that still looks great even when it's not applied perfectly.

Because paint can often scratch off these raised areas, a varnish is often used to protect the highlighting paint. But beware that varnishing a textured item can cause problems as it pools in the crevices or causes the brush to foam as you apply the varnish. But if your highlights aren't scratching or wearing off, you can skip the varnish.

These faux Czech glass beads were made from translucent Cernit polymer clay and were highlighted with gold paint to highlight the textured designs.

Accents and Dots

Another type of paint effect commonly used on polymer clay are dots and filigree or swirls used to apply a decorative accent. This is also where you would use a white dot to create a highlight in an eye to make it look more realistic. You can use a tiny paintbrush for this, but I'd use a ball stylus (aka dotting tool). You can also use paint pens for this. And btw, the rules for paint pens are the same as for any paint. Most work fine, but always test first. (Posca pens work great, btw.) These types of paint accents are usually not covered with a varnish.

Artistic Surface Effects

When talking about polymer clay, it can also be hard to separate painting out as a specific technique. Crackle effects, silkscreen printing, sponge painting through a stencil, acrylic paint pours, and many more processes use paint on polymer clay but have a whole world of technique and process to learn. (Learn about silkscreen printing in my eBook here.)

Many media are often combined to create complex surface effects using chalks, pastels, mica, powders, or dyes. (Yep, another in-depth eBook on Powders here!) The chemical rules of polymer clay and paint interactions still hold true for these processes, but I'm sure you can see how complicated it can get! This is the realm of personal experimentation. While you can learn some things from tutorials (such as my Rustic Beads Tutorial here), for most surface effects you'll head off into uncharted territory. But the good news is that it's great fun!

These Rustic Beads were made with Cernit polymer clay, paint, and magic. (You can buy the tutorial here!)

Types of Paint

I've read many "helpful" comments on social media that say you should only use water-based paint on polymer clay. But that is a gross oversimplification. (What about watercolor? Oil paints?) Here are some various types of paints that you might encounter and some pointers on how they might (or might not) be used well on polymer clay.

Acrylic Paint

While acrylic paint was invented in the 1950's by the companies that are now Liquitex and Golden, the term is not as specific as it once was. It's now a catch-all term for thick-bodied water-based paints. While high-end artist's acrylics do tend to contain emulsions of acrylic resin, student and craft level acrylic paints use cheaper materials including various vinyl binders and fillers that are chemically more similar to white glue.

Craft Acrylics

Craft acrylic paints come in a dizzying array of brands, types, varieties, formulations, colors, packaging, and quality. There are good craft paints and there are super cheap ones. Many acrylics are used nicely when working with polymer clay but as I stated above, there is huge variation and it's quite difficult to know if a specific brand or range will always work with polymer clay…or not. It just depends on what you want to do. Experiment! Be aware that craft paints often are produced with price in mind, so they do tend to carry a low pigment load or may even use fillers (such as chalk) instead of using pure pigments. They also tend to contain multiple pigments for each color.

Various craft paints that I've used when painting n polymer clay.

Artist's Acrylics

Artist's acrylic paints usually come in a tube and contain few cheap fillers. They usually contain a single, pure pigment and will be consistent from tube to tube. Soft-bodied artist's acrylics are similar but usually come in a bottle or jar. If you can afford it, this category will generally give you the best results for most times that you'd want to paint on polymer clay.

Here are some artist's acrylic paints that I've gathered over the years. These have rich pigment density and usually are not sticky on polymer clay.

Acrylic Inks

Acrylic inks are just acrylic paint in ink form. In other words, this product is thinned down enough to be used in a technical pen or marker. These are my top choice for painting polymer clay, actually! I have consistently had excellent results with Liquitex Acrylic Inks. Dr. Ph. Martin's Bombay India Inks are similar but tend to have poorer coverage and scratch off easily.

Acrylic inks can work nicely on polymer clay. I found that Liquitex Acrylic Ink had good coverage and didn't scratch off easily.

Oil Paints

Lots of people assume that you can't use oil-based paints and varnishes on polymer clay. That's a misunderstanding. They work great! In fact, oil paints are among the best for techniques which need a rich, multi-layered color effect. Beware that oil paints do take quite a bit longer to dry, however.

One tidbit to know, though, is that oil-based hobby paints tend to remain sticky on polymer clay. But it has little to do with the oil and everything to do with the paint's formulation. I've found that many acrylic hobby paints are also sticky on some brands of polymer.

Oil paints take a long time to dry, but bond nicely to polymer clay.

Genesis Heat-Set Oils

Long-time polymer clayers love these unique paints that go on like oil paints but never dry until they're cured with a heat gun or baked in an oven. Genesis paints are very expensive and typically only available from mail-order sources. They're often used to paint faces onto vinyl dolls. A fantastic benefit of these great paints is that they're never sticky on polymer clay. Why? Because they ARE polymer. Yes, they're made of the same heat-set vinyl plastisol that polymer clay is made from. These paints are an investment, but they're worth it for the serious polymer artist.

Watercolors

Watercolors are pure pigment plus a water-soluble binder (usually gum arabic). They're unique because they don't come packaged with a carrier or medium. You add the carrier (water) yourself. The water/pigment solution is applied to paper and it becomes permanent once the water dries. Watercolors are hard to use with polymer clay because they rely on the water spreading evenly on the surface and embedding into the fibers of the paper. Water just beads up on polymer clay.

Watercolors can be used on polymer clay (both raw and baked) for specific techniques, but other products and processes are necessary for it to work. Debbie Crothers uses watercolor inks in her Silkwater Splash tutorial. And Phyllis Cahill loves the delicate appearance that she can achieve when she paints onto prepared polymer clay with watercolors.

Specialty Paints

Some paints defy definition and have unique qualities that are even more difficult to discuss than we've seen thus far. Glass paint, glass enamel, Pebeo Prisme, crackle paint, and Unicorn Spit are some examples. Thes specialty paints are firmly in the realm of "your mileage may vary". You might have a stonking failure or you might discover a fun, new process. Experiment and enjoy!

Alcohol Inks

Technically not a paint, but I'm including alcohol inks here because they're used so often on the surface of polymer clay. These are dyes dissolved in an alcohol carrier. They have bright, clear colors. But beware that alcohol inks are made with dyes, and they, therefore, are not color-fast. They WILL fade in the light. Manufacturers do try to choose dyes that last longer, of course. But because alcohol ink sits on top of your baked clay, only a thin layer is present. Thinner layers fade faster. For more info on using alcohol inks with polymer clay (there's a lot to know), read my article here.

Conclusion

Painting polymer clay is great fun and can lead to some truly stunning results. But it can be more complicated than just applying some paint onto a little sculpture. There's a lot to consider from choosing the right paint to learning how to apply the paint neatly. Because of the complications that can happen and because of the very real possibility of ruining your project, you might prefer to create your item out of pure colored polymer clay. If you do choose to use paints on your polymer project, make sure to take the time to test the process and make sure you know how to get the results that you want. Now go have fun!

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Which Test Uses Color Change to Reveal Oil Based Paints

Source: https://thebluebottletree.com/painting-polymer-clay/

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