Quick answer: The best acrylic underpainting tips come down to three things: keep the first layer thin and lean (paint thinned with water or a fluid medium), limit yourself to one or two colors so you can focus on values, and let it dry fully before glazing or painting over it. A warm mid-tone such as burnt sienna or yellow ochre works for most subjects, and complementary underpaintings make colors on top look more vivid.
An underpainting is the first, simplified layer of a painting. It locks in your composition and your light-and-dark pattern before you spend time on color and detail. With acrylics it is especially useful, because the paint dries fast enough that you can block in a full underpainting and start the next layer in the same session.
This guide covers practical acrylic underpainting tips: which colors to choose and why, how thin to make the paint, the four main underpainting styles, a step-by-step method, and the mistakes that cause muddy or patchy results. If you are still putting together a basic kit, a small set is all you need for this stage, and our roundup of affordable acrylic paint sets under $30 covers starter options that include the earth tones underpaintings rely on.
What an Acrylic Underpainting Actually Does
Think of the underpainting as a map. It answers the big questions early: where the darkest darks sit, where the light falls, how shapes overlap, and whether the composition works at all. Fixing a misplaced horizon at this stage takes thirty seconds. Fixing it after three layers of color can take an afternoon.
It also does something purely visual. Small gaps between later brushstrokes let the underlayer show through, and that colored glow unifies the whole picture. A canvas left stark white tends to make colors look cold and disconnected, while a toned base gives everything a shared temperature.
Finally, it saves paint. Building opaque color directly on white often takes several coats, because many pigments (especially transparent ones like phthalo blue or quinacridone magenta) do not fully cover bright white. Over a mid-tone base, one or two layers usually do the job.
Acrylic Underpainting Tips for Choosing a Color
The color you choose sets the mood of the finished piece. There is no single correct choice, but each option behaves predictably.
| Underpainting color | Best for | Effect on final layers |
|---|---|---|
| Burnt sienna | Portraits, landscapes, still life | Warm glow; makes greens and blues feel natural rather than icy |
| Yellow ochre | Sunlit scenes, desert and autumn subjects | Soft warmth without overpowering lighter colors |
| Burnt umber | Dramatic, low-key paintings | Deep, moody base; good for strong value contrast |
| Ultramarine or Payne’s gray | Night scenes, winter, seascapes | Cool atmosphere; warm colors on top pop forward |
| Raw umber mixed with white (neutral gray) | Any subject when you want neutral color judgment | Lets you judge colors accurately without a temperature bias |
| Complementary color (e.g., red under green foliage) | Expressive, high-energy work | Vibrating color where gaps show through |
A useful rule: pick an underpainting that is the opposite temperature of your main subject. Warm earth tones under a blue-green landscape, or a cool blue under a sunset. The contrast creates life wherever the base peeks through.
Why earth colors are the default
Burnt sienna, raw umber and yellow ochre are inexpensive, dry quickly, and have moderate tinting strength. That last point matters. A high-strength pigment like phthalo blue can stain and bleed into every subsequent layer, while earth pigments sit back politely once covered.
How Thin Should the Underpainting Be?
Thin. This is the tip that solves the most problems. A good underpainting has the consistency of ink or light cream, not toothpaste.
- For a transparent wash: roughly 1 part paint to 2–3 parts water. Good for toning a whole canvas.
- For a value underpainting: roughly 1 part paint to 1 part water or fluid medium, so darks can be built up with a second pass.
- For a heavier, opaque grisaille: paint thinned only slightly with a glazing or fluid medium rather than lots of water.
Why not just add lots of water? Acrylic binder is what holds pigment to the surface. Most manufacturers suggest that diluting with more than about 30–50% water can weaken that film, which may lead to powdery or lifting paint on non-absorbent surfaces. On a primed canvas the gesso tooth helps, but if you want very thin, glossy washes, a fluid or glazing medium keeps the binder strong while still stretching the color.
Thick underpaintings also leave ridges. Every bump will show through later layers, catching light in places you did not intend.
The Four Main Underpainting Methods
Underpaintings come in a few classic styles. Choose the one that matches how you like to work and what the subject demands.
1. Toned ground (imprimatura)
A single, even, transparent wash across the whole surface. No drawing, no values, just color. It takes five minutes and instantly removes the intimidating white. Wipe it on with a large flat brush or a rag, then let it dry before sketching.
2. Monochrome value study (grisaille or brunaille)
You paint the full image in one color, shifting only from light to dark. Grisaille uses grays; brunaille uses browns; verdaccio (traditionally a green-gray) is popular for portraits because it neutralizes pinkish skin tones. This is the method that teaches the most, because it forces you to see values separately from hue.
3. Block-in (local color underpainting)
Each major shape gets a flat, simplified version of its eventual color. Sky gets a mid blue, trees a dull green, a red barn a muted red. It is fast and suits loose, painterly styles where you plan to leave lots of the base visible.
4. Complementary underpainting
Here you deliberately use the opposite color of what will go on top: orange under a blue sky, red under foliage, violet under yellow fields. When later strokes leave tiny gaps, the complementary flashes give the surface a lively, almost vibrating quality. It is used often in impressionist-inspired work.
Step-by-Step: A Simple Acrylic Underpainting
This process suits a landscape or still life on a primed canvas or panel. Allow about 30–60 minutes for an 11 x 14 inch surface.
- Tone the surface. Brush a thin wash of burnt sienna or yellow ochre over the canvas. Wipe back with a paper towel if it looks too strong. Let it dry, which normally takes 10–20 minutes for a thin layer.
- Sketch the main shapes. Use a thinned darker color (burnt umber works well) and a small round brush. Keep it to big shapes: horizon, major masses, the main subject’s outline. Skip detail.
- Squint and map the darks. Half-close your eyes to simplify the scene into light, medium and dark. Fill the darkest shapes with a slightly stronger mix of your underpainting color.
- Add mid-tones. Use a lighter dilution of the same color for medium values. You are aiming for three to four clear value steps.
- Lift out the lights. While the paint is still damp, use a clean, barely moist brush or a rag to pull paint away where the brightest lights will go. Acrylic dries fast, so work in sections.
- Step back and check. Look at the underpainting from across the room or in a phone photo turned to grayscale. If the composition reads clearly now, it will read clearly when finished.
- Let it dry completely. Thin acrylic layers are usually touch-dry in under 30 minutes. Give it a little longer if you used any medium or a thicker mix, since painting over a tacky layer can lift it.
Acrylic Underpainting Tips by Skill Level
For beginners
- Start with a toned ground only. It is the least risky way to see how a colored base changes your final colors.
- Use one color plus water. Adding more colors to the underpainting invites mud.
- Limit values to three: light, middle, dark. More steps can come with practice.
- Keep a spray bottle nearby to slow drying while you work out shapes.
For intermediate painters
- Try a full grisaille or brunaille, then glaze transparent color over it. This is a classic way to get depth with relatively few layers.
- Experiment with a complementary underpainting on one area only, such as orange beneath a sky, to see the effect before committing to a full canvas.
- Use a fluid medium instead of water for darker passages to keep the paint film strong.
For advanced work
- Vary the underpainting color across the canvas: warm in the foreground, cool in the distance, to reinforce atmospheric perspective.
- Leave deliberate passages of underpainting untouched in the final work for texture and unity.
- Consider an isolation coat of clear gloss medium over a finished underpainting, so later corrections can be wiped back without disturbing the base.
Common Underpainting Mistakes (and Fixes)
| Problem | Likely cause | Fix |
|---|---|---|
| Final colors look muddy | Underpainting color too strong or too many hues mixed in | Use one earth color, dilute more, and let it dry before adding color |
| Underpainting lifts when painting over it | Layer was not fully dry, or was over-diluted with water | Wait longer; use a medium instead of extra water for thin layers |
| Ridges or brush marks show through | Underpainting applied too thick | Keep the base thin; sand gently once dry if needed |
| Composition still feels wrong | Too much detail too early hides the big shapes | Check the value pattern in grayscale before moving on |
| Base color bleeds through every layer | Staining pigment (e.g., phthalos, quinacridones) used for underpainting | Switch to earth pigments, or seal with a gloss medium isolation layer |
| Darks look flat and lifeless on top | Underpainting darks were painted with black | Mix darks from umber plus ultramarine for a richer base |
Which Paint Works Best for Underpainting?
You do not need professional-grade paint for this layer. Since most of it will be covered, student-grade acrylics are perfectly sensible. What matters more is:
- Good earth colors. A set that includes burnt sienna, burnt umber, raw umber or yellow ochre gives you every classic underpainting option.
- Fast, flat drying. Most acrylics dry with a satin or matte sheen, which accepts the next layer well.
- Fluid or soft-body consistency. These thin more evenly than heavy-body tubes, though either can be diluted.
Save your premium, high-pigment paints for the final layers where color intensity shows. Many painters keep a separate, inexpensive tube of burnt sienna just for toning and underpainting.
Do You Need to Seal an Underpainting?
Usually no. Acrylic dries into a water-resistant film, so once fully dry it will not re-dissolve when you paint over it. That is a big advantage over watercolor or gouache underpaintings.
There are two exceptions. If you heavily diluted the paint with water, the layer may be slightly fragile and a thin coat of matte or gloss medium will reinforce it. And if you plan to scrub or wipe back later layers, an isolation coat provides a safety barrier.
Can You Underpaint for Oils Using Acrylic?
Yes, this is a common practice. Acrylic dries fast, so you can block in a composition and begin oils the same day. The general rule is that oil can go over acrylic, but acrylic should not go over oil. Keep the acrylic underpainting thin and lean, and avoid very glossy, slick acrylic surfaces, since oil paint grips better to a slightly matte, toothy layer. Some oil paint and acrylic manufacturers advise checking their guidance, as adhesion depends on the products used.
FAQs
What color should an acrylic underpainting be?
Burnt sienna is the most popular all-purpose choice because its warmth flatters greens, blues and skin tones. Use cool blues or grays for night and winter scenes, a neutral gray when you want unbiased color judgment, or a complementary color for vivid, energetic results.
How long should an acrylic underpainting dry?
Thin washes are typically touch-dry in 10–30 minutes, depending on humidity and airflow. Thicker mixes or layers with added medium can take longer. Wait until the surface no longer feels cool or tacky before painting on top.
Should an underpainting be dark or light?
A mid-tone works best for most paintings because you can push both lights and darks from there. Very dark underpaintings suit dramatic, low-key subjects, while a light toned ground is better for airy, high-key work.
Can I use watered-down acrylic for underpainting?
Yes. Water is fine for thin washes on primed canvas. For very diluted layers, or on slick surfaces, a fluid or glazing medium helps preserve adhesion because heavy dilution can weaken the acrylic binder.
Does the underpainting need detail?
No. Keep it to big shapes and clear values. Detail added at this stage usually gets painted over and can distract you from checking whether the composition and lighting work.
Is a grisaille the same as an underpainting?
A grisaille is one type of underpainting: a monochrome value study painted in grays. Other types include toned grounds, brown brunailles, color block-ins and complementary underpaintings.
Next Step
Underpainting is one of the cheapest ways to make your acrylics look more finished: thin paint, one or two earth colors, clear values and patience while it dries. Try a burnt sienna toned ground on your next canvas and compare it to one started on white.
To gather the earth tones and basic colors this technique needs without overspending, see our picks for budget-friendly acrylic sets that still deliver vibrant color, and choose one with a good range of browns and ochres for your underpainting stage.
