Quick answer: In the tempera vs poster paint question, the two products sold for kids and classrooms are close cousins: both are water-based, opaque, matte, washable, and inexpensive. “Tempera” in a school catalog usually means a liquid washable paint with a starch, gum, or cellulose binder, while “poster paint” is a thicker, slightly glossier version of the same idea made for bold, flat color on paper. Poster paint tends to be more opaque and more vivid; school tempera is usually thinner, more economical, and easier for small hands to spread. Neither is permanent, and neither is the same as traditional egg tempera used by fine artists.
Two shelves in the same craft aisle, two nearly identical squeeze bottles, two different names. Parents and teachers run into this constantly, and the labels do not help, because manufacturers use “tempera,” “poster paint,” “poster color,” and “washable paint” loosely and sometimes interchangeably.
This comparison untangles the terms, puts the two paints side by side on the properties that matter for children’s projects, and then gives a verdict by use case rather than a single winner. If what you really want is a shortlist of safe, bright paints for a kid’s table, the roundup of the best non-toxic poster paints for kids does that job; this article explains what you are choosing between.
Three Things Called “Tempera”
Most of the confusion in tempera vs poster paint comes from one word doing three jobs.
Egg tempera is the historical fine-art medium: dry pigment ground into egg yolk and water, applied in thin hatched layers on a rigid gesso panel. It dries fast, cures hard over months, and is extremely permanent. It is sold as a specialty product and is not what a school supply list means.
School or “washable” tempera is a liquid, pre-mixed paint built on a non-toxic binder, commonly a starch, dextrin, or methylcellulose base with glycerin to keep it from drying out in the bottle. It is matte, opaque, washable from skin and most fabrics, and designed to be cheap by the gallon. This is the tempera in the kids’ aisle.
Tempera cakes or blocks are the same washable formula pressed into solid pucks. You wet a brush and lift color like a watercolor pan, but the result is opaque rather than transparent.
When this article says “tempera,” it means the second and third types, because those are the ones people actually compare with poster paint.
What Poster Paint Actually Is
Poster paint grew out of sign painting and show-card lettering, where the goal was flat, solid color that covered in one coat and photographed or read well from a distance. The modern craft version keeps that priority. It is a water-based paint with a gum arabic, dextrin, or similar water-soluble binder, loaded with more pigment and filler than school tempera so that it covers thoroughly and looks saturated.
Some “poster colors” sold in jars, especially those marketed to students in Asia and Europe, are essentially a budget gouache: dense, velvety, and re-wettable after drying. Others, labeled “poster paint” in US craft stores, are basically a heavier-bodied tempera. The name tells you about the intended look, not a strict chemistry.
Both paints share a defining trait: the binder stays water-soluble after drying. A dried poster paint or tempera painting will lift, smear, or run if it gets wet again. That is why they wash out of clothes so well, and also why they are never used for anything that must last outdoors or be handled often.
Tempera vs Poster Paint: Side-by-Side Comparison
| Property | School Tempera (liquid) | Poster Paint |
|---|---|---|
| Binder | Starch, dextrin, or cellulose, water-soluble | Gum arabic or dextrin, water-soluble |
| Consistency | Thin to medium, pours from a bottle | Medium to thick, often creamy or paste-like |
| Opacity | Good; may need two coats on dark paper | Very high; usually covers in one coat |
| Finish | Flat, chalky matte | Matte to soft satin, slightly richer |
| Color intensity | Bright but can look dusty when dry | Vivid and saturated |
| Drying time | Fast, roughly 5 to 15 minutes for a thin layer | Slightly slower where applied thickly |
| Re-wettable after drying | Yes | Yes |
| Cracking risk | Low when thin; flakes if layered heavily | Higher if applied thickly or on flexible paper |
| Washability | Excellent from skin, tables, most clothing | Good; some intense colors can tint fabric |
| Best surfaces | Construction paper, newsprint, cardboard, egg cartons | Poster board, card stock, heavy paper, papier-mache |
| Typical cost | Lowest per ounce, sold in pints to gallons | Higher per ounce, sold in small jars or sets |
| Typical age range | Toddler through elementary | Preschool through teen and adult hobby |
The pattern in that table is simple. Tempera is optimized for volume and cleanup; poster paint is optimized for looks. Everything else follows from those two priorities.
How They Differ in Practice
Coverage and layering
Poster paint’s higher pigment and filler load means a single pass of yellow over black construction paper reads as yellow. Thin school tempera often shows the dark paper through until a second coat goes on. For posters, signs, and anything where flat color matters, that is poster paint’s main advantage.
Layering works for both, with a catch. Because the dried film stays soluble, a wet brush scrubbing over a dried layer will pick it up and muddy the new color. The workaround is the same for either paint: let the first layer dry fully, use a loaded brush, and lay the new color down in one or two strokes rather than scrubbing.
Cracking and flaking
Any water-soluble, high-filler paint cracks when it dries thick on a surface that flexes. Poster paint, being thicker and more heavily loaded, is more prone to this on standard printer paper or thin construction paper. School tempera applied in a thin wash rarely cracks but will flake off smooth plastic or glossy surfaces because it has nothing to grip.
The fix is surface choice. Heavier paper, poster board, cardboard, and papier-mache give both paints enough absorbency and stiffness to dry without cracking.
Washability
Most liquid temperas labeled “washable” rinse out of cotton with cold water and a normal wash cycle even after drying. Poster paints vary more. The budget types behave like tempera, but denser poster colors with staining pigments such as some magentas and violets can leave a faint tint on light fabric if they dry in. Pretreating the stain with dish soap before washing handles most cases.
Smell, texture, and feel
School tempera smells faintly of starch or nothing at all and feels slippery. Poster paint has a creamier, almost frosting-like body that older kids enjoy for impasto-style texture, stenciling, and sponge work, where thin tempera would just soak in.
Acrylic Gouache vs Watercolor vs Poster Paint
Because the shelf next to tempera and poster paint holds watercolors and, increasingly, acrylic gouache, it helps to see all of them together. Each solves a different problem.
| Paint | Binder | Permanent when dry? | Opacity | Price tier | Best for kids when |
|---|---|---|---|---|---|
| School tempera | Starch or cellulose | No, re-wets | Medium-high | Lowest | Mess is expected and volume matters |
| Poster paint | Gum or dextrin | No, re-wets | Very high | Low | Bold flat color on card or poster board |
| Watercolor (pan) | Gum arabic | No, re-wets | Transparent | Low to mid | Minimal mess, washes, learning water control |
| Traditional gouache | Gum arabic, high pigment | No, re-wets | Very high | Mid to high | Older kids doing illustration |
| Acrylic gouache | Acrylic polymer, matte | Yes, waterproof | Very high | Mid to high | Projects that must survive handling |
| Student acrylic | Acrylic polymer | Yes, waterproof | Medium-high | Low to mid | Canvas, wood, outdoor crafts |
The dividing line that matters most for a household is permanence. Tempera, poster paint, watercolor, and traditional gouache all stay water-soluble, so they come out of clothes and off tables. Acrylic gouache and student acrylic cure into a plastic film within minutes and will not wash out once dry. That single fact decides a lot: a four-year-old gets tempera or poster paint; a twelve-year-old painting a birdhouse gets acrylic.
Verdict by Use Case
Rather than crown a winner, match the paint to the job.
Toddler and preschool art (ages 2 to 5)
Choose liquid school tempera. It is the cheapest to pour liberally, the easiest to wash off skin and hair, and thin enough that a chunky brush or fingers can move it. Poster paint’s thickness is wasted here and its stronger pigments are slightly more likely to tint clothes.
Posters, signs, and science fair boards
Choose poster paint. One-coat coverage on poster board, crisp edges when stenciled, and saturated color that reads from across a gym are exactly what it was made for. Thin tempera streaks and needs a second coat for the same result.
Classroom bulk use and group murals on paper
Choose tempera. Gallon jugs, pump dispensers, and easy cleanup make it the practical option. Use heavier kraft or butcher paper to limit flaking as the mural gets rolled.
Papier-mache, cardboard models, and egg carton crafts
Either works; poster paint looks better. Both grip absorbent surfaces well. Poster paint’s opacity hides newsprint text in one coat. If the finished piece will be handled often, a coat of clear water-based sealer protects either paint from fingerprints and humidity.
Rock painting, wood, and anything outdoors
Choose neither. Both paints are water-soluble and will run in rain or dew and flake off smooth stone and sealed wood. This is where acrylic or acrylic gouache belongs.
Older kids and teens learning illustration
Choose a dense poster color or an inexpensive gouache. The creamy body teaches brush control and flat-color technique that transfers directly to gouache and acrylic later. Tempera’s thin, chalky film is less satisfying at this stage.
Tight budget for a lot of kids
Choose tempera. On a per-ounce basis it is the least expensive opaque paint available. Reserve a few jars of poster paint for projects where coverage and color intensity are the point.
Tips for Getting the Best From Either Paint
- Shake or stir before use. Both paints separate in storage, with binder rising and pigment settling. Unmixed paint looks weak and dries unevenly.
- Thin with a little water, not a lot. A few drops improve flow. Too much water breaks the binder-to-pigment ratio and the dried paint rubs off as powder.
- Match paper weight to paint thickness. Thin tempera on construction paper is fine; thick poster paint needs card stock or poster board to avoid cracking and warping.
- Dry flat. Hanging a wet poster-paint piece lets heavy paint sag and crack along the drips.
- Keep lids tight and bottles upright. The glycerin in these paints slows drying, but open containers skin over and the skin flakes into the paint.
- Add a drop of dish soap to tempera when painting on slick surfaces like foil or plastic lids. It helps the paint wet the surface instead of beading, though adhesion is still temporary.
- Seal only if needed. A spray or brush-on water-based sealer protects finished work, but a brush can smear poster paint, so a light spray is the safer method.
Common Mistakes When Choosing Between Them
Assuming “tempera” means archival. A parent who has heard of Renaissance egg tempera may expect school tempera to be permanent. It is not; it washes off with a damp sponge.
Buying poster paint for finger painting. The thick body is hard for toddlers to spread, uses up a small jar quickly, and the vivid pigments are a little more likely to stain. Thin tempera or a dedicated finger paint is the better match.
Using either on canvas. Primed canvas is flexible and slightly slick. Both paints crack and flake on it over time. Student acrylic is the right choice for canvas.
Mixing brands and types in one bottle. Different binders can curdle or separate. Mix only on the palette.
Expecting one coat from thin tempera on dark paper. Plan on two coats, or switch to poster paint for that job.
Safety and Labeling
In the United States, children’s art materials should carry the ACMI AP (Approved Product) seal or a conformance statement to ASTM D-4236, which indicates the formula has been evaluated by a toxicologist and found to contain nothing in quantities harmful to humans, including children. Most school temperas and craft poster paints sold in US stores carry this certification, but imported poster colors sometimes do not, so check the label. The guide to vibrant, non-toxic poster paints for children focuses on products that meet these standards.
“Non-toxic” does not mean edible. These paints can still upset a stomach if swallowed in quantity, and glitter or metallic versions may contain particles that should stay out of mouths. Supervise toddlers and keep the paint on paper and skin.
FAQs
Is tempera paint the same as poster paint?
Not exactly, but they are close. Both are water-soluble, opaque, washable paints for paper. School tempera is thinner and cheaper; poster paint is thicker, more opaque, and more saturated. Some manufacturers use the names interchangeably, so judge by consistency and coverage rather than the label.
Which is better for kids, tempera or poster paint?
For toddlers and preschoolers, tempera is better because it is thin, cheap, and the easiest to wash out. For school-age kids making posters, models, or detailed paintings, poster paint gives stronger color and one-coat coverage.
Does poster paint wash out of clothes like tempera does?
Usually, yes, especially if it is labeled washable and treated before it fully dries. Deeply pigmented poster colors can leave a faint tint on light fabric. Rinse in cold water, work in a little dish soap, and launder normally.
Can you mix tempera and poster paint together?
Yes, on the palette. Both are water-based with compatible soluble binders, so small amounts mix without curdling. Avoid pouring one into the other’s bottle, since different preservatives and thickeners can separate over time.
Is poster paint the same as gouache?
Poster paint is often described as a budget gouache. Both are opaque, matte, and re-wettable. Gouache uses finer, more concentrated pigment and less filler, so it is smoother, more lightfast, and far more expensive. For children’s work, poster paint is the practical substitute.
Can you use tempera or poster paint on wood or rocks?
You can, but neither will last. Both stay water-soluble and will flake or wash off with moisture and handling. For rocks, wood, or anything outdoors, use acrylic paint, which dries to a waterproof film.
Final Thoughts
Tempera and poster paint sit on the same branch of the paint family tree. One is tuned for cheap volume and easy cleanup, the other for coverage and color punch, and both wash out and stay impermanent by design. Pick tempera when the painter is small or the class is large, and pick poster paint when the finished piece needs to look bold on poster board or card.
When you are ready to stock the craft shelf, start with the roundup of safe, bright poster paints that work well for kids’ projects, which covers the certification, bottle sizes, and color ranges worth comparing before you buy.
