Acrylic and oil paints are two of the most popular types of paints artists use. But due to their different chemical compositions, many painters wonder if mixing the two mediums is possible. This article will provide a comprehensive overview on blending acrylics and oils, including the risks, techniques, and alternatives.
The Chemical Composition of Acrylic vs. Oil Paint
To understand why acrylics and oils don’t mix well, it’s important first to examine what each medium is made of.
Acrylic paint is water-based, meaning the pigment is suspended in an acrylic polymer emulsion. The acrylic binder is plastic-based, so acrylic paints dry to a plastic-like finish.
The main components of acrylic paint include:
- Pigment – colored particles that provide color to the paint
- Acrylic polymer – the acrylic plastic binder that holds the pigment together
- Water – the solvent used to thin acrylic paint
- Extenders – substances like calcium carbonate used to bulk up the paint
- Surfactants – soaps that improve the flow and surface tension
Oil paint gets its name from using oils as a binder for the pigment. Traditional oil paint uses drying oils like linseed, poppy, and walnut oils. The oils take a long time to cure and dry fully.
The primary ingredients of oil paint include:
- Pigment – just like acrylics, this provides color
- Drying oils – such as linseed or safflower oil act as the binder
- Solvents – such as turpentine or mineral spirits are used for thinning
- Driers – metal soaps like cobalt that speed up drying time
- Varnishes – resins help increase glossiness
As you can see, the main difference lies in the binder. Acrylic polymers are plastic-based while oil paint uses actual oils. This disparity in composition is the main reason the two mediums don’t mix well.
Why Acrylic and Oil Paints Don’t Mix
There are a few key reasons why blending acrylics and oils is problematic:
They Have Different Polarity
- Acrylics are polar, meaning they use water as a solvent. Water molecules are polar.
- Oils are non-polar, meaning they repel water. Oil and water don’t mix.
- This polarity difference prevents proper blending and binding of the two paints.
Acrylics Dry Faster
- Acrylic paint dries quickly, within minutes or hours. This is due to its water-based acrylic polymer binder.
- Oils take much longer to dry, from days to weeks, due to the slow-drying oils used.
- The fast drying acrylics can form a skin over slow-drying oils, preventing proper bonding and curing.
Oils Break Down Acrylics Over Time
- Oil paints remain flexible and somewhat permeable after they dry.
- The oils may eventually penetrate the acrylic layer underneath, causing breakdown.
- This can result in cracking, peeling, bubbling, and other paint adhesion issues over time.
Paint Properties Change
- Mixing the mediums can affect both paints’ handling, drying time, viscosity, and other properties.
- The paints may separate, get stringy or oily, dry at different rates, or act unpredictably.
Differences in Flexibility
- Acrylic paint becomes rigid and inflexible when dry.
- Oil paint remains somewhat flexible when cured.
- If oil paint is on top of acrylics, this can cause cracking as the acrylic can’t flex.
- Pigments can interact differently in acrylics vs oils and cause unintended color shifts.
- The fast drying acrylic may turn matte or pale compared to oils.
Due to all these issues, most artists don’t recommend blending acrylics and oils directly. But there are some limited exceptions.
Exceptions Where Acrylics and Oils Can Mix
While acrylic and oil paints generally don’t mix, there are some specific scenarios where blending them is possible:
Water-Mixable Oil Paints
- Some modern oil paints are formulated to thin and clean up with water instead of solvents.
- Known as water-mixable or water-soluble oils, these contain an emulsifier that allows mixing with water.
- Water-mixable oils can be thinned and blended with acrylic mediums, gels, or polymers.
- They provide a similar painting experience as acrylics. But the paint remains oil-based when dry.
- Adding acrylic mediums like gloss gels to oil paint is possible.
- The mediums can alter consistency and sheen but may speed up drying time.
- Acrylic retarders or flow improvers can also add flexibility when mixed into oils.
Oils as a Top Layer
- Applying oils on top of acrylic paint is generally considered safe.
- The acrylic provides a dry, flexible base layer for the oils to adhere to without direct mixing.
Acrylic Underpainting with Oils on Top
- Acrylics make an excellent underpainting below oil paint due to fast drying.
- The acrylic layer provides texture and depth for the oils on top.
Specialty Mixing Mediums
- Some mediums are designed specifically to blend acrylic and oil paints.
- These contain chemical emulsifiers that bind to both polar and non-polar paints.
- Examples include AMACO’s Acrylic-Oil Blend and Matisse’s Derivan Acryloil.
If you want to mix acrylics and oils, it’s best to stick to these limited techniques for good adhesion and archival stability. Always check the manufacturer’s recommendations as well.
Risks of Mixing Acrylics and Oils
While the above techniques can allow blending of acrylic and oil paints successfully, there are still some potential downsides and hazards to be aware of:
- Paint adhesion issues – Acrylics may chip, flake, or separate from oils over time. Proper bonding is difficult.
- Cracking and peeling – Flexible oils on top of rigid acrylics can crack as the paints expand and contract at different rates.
- Muddying of colors – Acrylics tend to dry slightly darker. Mixing the paints can dull the vibrancy.
- Changing of paint properties – Blending alters viscosity, drying time, and handling in unpredictable ways.
- Shortened workability – Acrylics speed up the drying time of oils, requiring faster techniques.
- Yellowing over time – Oil paint layers may become transparent and reveal acrylic underlayers.
- Difficult archival stability – Keeping mixed paints stable over many decades can be problematic.
Proceed with caution and test samples when mixing acrylics and oils. Traditional oil over acrylic methods remain the safest option.
Traditional Oil Over Acrylic Painting Techniques
If you want to use acrylics and oils together in the traditional layered method, here are some tips:
Paint the Underpainting First
- Apply all acrylic underpainting layers first and allow to fully dry. This may take 24-48 hours.
Seal Absorbent Canvases
- Prime canvas with acrylic gesso or medium before underpainting to prevent oil absorption.
Choose Stiff Acrylic Brushes
- Stiff bristle brushes work better than soft sable hair when applying acrylic underpainting.
- Use thick acrylic paint and brush strokes to add visual texture for the oils.
Focus on Composition and Values
- Don’t spend too much time on details in the acrylic underpainting. Just focus on basic forms and values.
Let Acrylics Dry Thoroughly
- Ensure acrylic layers are fully cured before adding oils to prevent cracking.
Start with Lean Oils First
- Begin with oil paint thinned with solvents and mediums (lean) before moving to thicker oils.
Use Flexible Oil Brushes
- Soft sable or synthetic brushes work best for smoothing and blending oils.
Slow Drying with Mediums
- Add oil mediums to slow the drying time when painting over acrylics.
Follow these best practices for good adhesion and minimal cracking when painting oils over acrylics.
Common Acrylic and Oil Painting Techniques
Beyond just layering oils over acrylics, there are some other creative techniques artists can use to take advantage of the unique properties of each medium:
Acrylic Wash – Thin translucent acrylics with lots of water or acrylic mediums create transparent acrylic washes. These can suggest textures and colors before going over in oils.
Acrylic Impasto – Use thick, buttery acrylic paint to create texture and raised brush strokes. This provides depth and interest for the oils layered on top.
Acrylic Collage – Collage papers, fabrics, found objects to the acrylic underpainting. This adds visual interest the oil paints can play off.
Sgraffito – Scratch into wet acrylic paint layers with the end of a brush or painting tool to reveal underlying colors. This etched texture remains when oils are applied over it.
Dry Brush – Apply thick acrylic paint with a dry brush to make textured, broken color effects. Oils glazed over this can unify the look.
Wet Blending – Wet acrylics can be gently blended with a damp brush to soften edges before drying. This creates smoother transitions for the oil paint.
Scumbling – Apply opaque acrylic paint in broken patches over dry paint, leaving some underlayer showing through. Oils scumbled on top increase depth.
Glazing – Thin, transparent layers of oil paint can be glazed over acrylic underpaintings. This deepens color and adds luminosity.
Impasto – Buttery oil paint can be used thickly to stand out in relief over thin acrylics. The acrylic texture shows through the brush strokes.
Wet on Wet – Oil colors rapidly blended into each other while wet create natural gradients and textures. The acrylic base unifies the effect.
Dry Brush – Stiff bristle brushes apply broken strokes of thick oil paint over acrylics. This makes textural accents and variations.
Blending – Soften transitions between oil colors wet or by scumbling lighter paint into darker colors while still wet. Acrylics stabilize the blended oils.
Glazing – Multiple thin, transparent layers of oil glazes build up depth and luminosity over acrylic underpaintings.
Scraffito – Etch linear designs through oil paint layers wet to reveal the acrylic basecoat underneath. Acrylics make the etched effect more visible.
Textural Effects – Use acrylic gels and pastes to create thick sculptural textures for oil colors on top. The acrylic base makes the texture more defined.
Washing – Thinned oil paint may be loosely washed over dry acrylics. The acrylic layers add texture while the oils create transparency.
Recommended Acrylic and Oil Color Palettes
Choosing compatible pigments is important when blending acrylics and oils. Here are some recommended color palettes:
Titanium White – mixing and lightening
Cadmium Red – strong red
Alizarin Crimson – deep red
Cadmium Yellow – bright yellow
Azo Yellow – transparent yellow
Ultramarine Blue – neutral dark blue
Phthalo Blue – bright transparent blue
Burnt Sienna – earthy brown
Titanium or Zinc White – mixing
Cadmium Red Light – orange-leaning red
Alizarin Crimson – deep bluish red
Cadmium Lemon – light yellow
French Ultramarine – neutral blue
Phthalo Green – bright transparent green
Burnt Sienna or Umber – earth tones
Choose paints with the same pigments for color consistency between acrylics and oils. Avoid filler pigments like PW6 in acrylics. Stick to pure, lightfast pigments.
Palette Knife Techniques with Acrylics and Oils
Beyond just brushes, painters can use a painting knife to create thick textural effects in both acrylics and oils:
Impasto – A palette knife adds thick texture and raised ridges of paint. Acrylic impasto makes dramatic relief for oils.
Textural Accents – Dab palette knife marks sparsely to create high paint points. This adds dimensional texture for oils to play off.
Color Mixing – Mix paints directly on the canvas with a knife. Acrylics can be mixed smoothly before the oils are applied over them.
Scrape Away – Remove wet acrylic paint with a knife’s edge to reveal underlying paint. This scraping reveals points of interest for oil layers.
Smooth Away – A knife can smooth and blend wet acrylics before drying. Oils can sharpen and refine the softened acrylic textures.
Additives – Mix heavy body acrylics on a knife with sand, glass beads, or pumice gels to create coarse, gritty texture for oils.
Underpainting – Use large areas of solid acrylic underpainted with a palette knife. Oils added on top can bring it to life.
Edge Control – A painting knife keeps acrylic brush strokes controlled. Oils can then be smoothed into the plastic-like acrylic edges.
Contrasting Marks – Use a knife to make textural oil marks on top of smooth acrylics or overlapping two distinct acrylic knife techniques.
Scraping Oils – Wet oil paint can also be easily scraped away with a painting knife over dry acrylics to create negative space.
Cleaning Palettes and Brushes with Acrylics and Oils
Clean palettes and brushes thoroughly between acrylics and oils:
Dedicated Palettes – Use separate palettes for acrylics and oils to prevent cross-contamination. Disposable paper or stay-wet palettes are recommended.
Immediate Acrylic Cleaning – Clean acrylic brushes and palettes with soap and water before paint dries. Avoid needing harsh solvents.
Oil Paint Thinners – Use odorless thinners to clean oil paint from brushes and palettes. Follow with soap and water.
Avoid Cross-Use of Solvents – Don’t use the same solvents or mediums when switching between acrylics and oils. Keep them separate.
Brush Combs – Use a metal brush comb to remove paint residues from brushes when switching between acrylic and oil.
Brush Conditioner – Rinse brushes with brush cleaner or conditioner after intensive painting sessions involving both mediums.
Dry Thoroughly – Allow brushes to dry fully between acrylic and oil use. Moisture remaining in the ferrule can cause oils to destabilize.
Dedicated Brushes – Use separate brushes for acrylics and oils whenever possible. This prevents cross-contamination.
Label Supplies – Keep acrylic and oil paint tubes, jars, solvents, mediums, and tools labeled clearly for easy identification.
Thorough cleaning habits prevent paint mixing mishaps. Never try to use the same solvents or water to clean both mediums.
Storing Mixed Acrylics and Oils
Storing pre-mixed acrylic and oil paint requires some special considerations:
- Store paint mixtures in sealed metal tins or glass jars – plastics can degrade oil paint over time.
- Avoid storing paints mixed on a palette – only mix amounts that will be used up in one session.
- Spray water over acrylics and use a wet palette for oils to help keep them workable as long as possible.
- Add a few drops of glycerin or acrylic retarder to mixed oil paints to slow drying time in the jar.
- Lay plastic wrap directly on the surface of wet oil paint mixtures to prevent oxygen exposure while storing.
- Check stored paints for mold or bacteria growth and signs of deteriorating stability over time.
- Discard unstable mixed paints, especially oil and acrylic mixtures, after a few months at most. Do not use old paint.
- Properly dispose of unused paint mixtures since the blended mediums can’t be separated for recycling.
- Avoid storing mixed paints or multiple half-used tubes and jars. Only mix what you will immediately use up.
For best results, minimize stored mixed media paintings. Use up customized blends in one session whenever possible.
Troubleshooting Problems When Mixing Acrylic and Oil Paints
If you do blend acrylics and oils, here are some common problems and solutions:
- Increase humidity when applying oil over acrylic.
- Allow acrylic underlayers to dry up to a week before adding oils.
- Add wax medium or adhesive gel to the oils for better acrylic bonding.
- Wait for acrylic layers to dry first fully.
- Apply thinner coats of oil glazes rather than thick paint.
- Use more wax or alkyd medium in the oil paint.
- Wet acrylic underlayers are the most common cause. Ensure acrylics are dry.
- Apply oil in thin layers and wait longer between coats.
- Don’t apply thick impasto oils over smooth acrylics. Use textured acrylic underpainting.
- Gently sand acrylic layers first to increase surface tooth and adhesion.
- Use an isolation coat like gamblin’s Galkyd on acrylics before oil painting.
- Add acrylic polymer medium to oils to reduce tackiness.
- Use wax emulsions in oil paint to decrease grab.
- Mist area with solvent and gently blot sticky oil paint.
- Avoid using low quality filler white acrylics like PW6 that yellow over time.
- Apply isolation coat on acrylics before oil glazing.
- Use lightfast pigments less prone to fading.
Muddying of Colors
- Test a small sample before mixing paints to see color shifts.
- Adjust and compensate colors in the acrylic underpainting.
- Use very thin translucent oil glazes over acrylics.
Changes in Paint Properties
- Add oil painting mediums to acrylics and acrylic polymers to oils before mixing to improve compatibility.
- Do not add straight oils into acrylics. Only use formulated mediums.
- Test mixtures and drying times on a canvas sample first.
If you experience any of these issues, the paints may be incompatible. Stick to traditional oil over acrylic methods.
Best Surfaces for Acrylic and Oil Mixed Media
Choosing the right painting surface helps avoid adhesion problems with mixed media:
- Canvas – Acrylic primed canvas works for both acrylics and oils. Prime raw canvas first.
- Wood – Use wood panels sealed with gesso rather than raw wood that may absorb oils.
- Paper – Heavy watercolor paper works for acrylics. For oils, use canvas paper mounted on board.
- Board – Composite boards prepared with acrylic gesso are suitable for both mediums.
- Glass – Use for acrylics only. Do not use oils since they require a flexible surface.
- Metal – Apply an isolation coat first. Unprimed aluminum or steel can react with oils.
Prep surfaces like wood, paper, or board with acrylic gesso before use. Avoid very absorbent materials for oils but too slick for acrylic adhesion.
Photo References with Acrylics and Oils
When working from photo references with mixed media, use these tips:
- Reproduce the image outline in acrylics first to act as an underpainting for oils.
- Print photos on paper or acrylic medium and transfer or collage into acrylic underpaintings.
- Project images on canvas using an overhead projector. Trace outlines in acrylics before oils.
- Grid out and enlarge images using acrylic on canvas before freehand painting in oils.
- Paint acrylic photo collages with printed photos before using oils to paint more realistic elements on top.
- Paint backgrounds wet-on-wet in acrylics. Use oils for detailed realism after drying.
- Brush on a sepia or grey acrylic wash layer first for monochromatic shading. Add oils for color later.
Working over top of acrylic photo transfers or collages can add stability and structure before painting oils. Take advantage of acrylic’s fast drying time.
Common Substrates for Acrylic and Oil Mixed Media
In addition to traditional canvas or boards, acrylics and oils can be used on many different painting surfaces:
- Wood products – MDF, birch, poplar
- Metal – Steel, aluminum, copper
- Glass – Plain glass or plexiglass
- Stone – Smooth river rocks, slate, granite scraps
- Fabric – Canvas, denim, muslin, linen
- Leather – Vegetable tanned leather for oils
- Paper – Watercolor paper, printmaking paper
- Plaster – Primed plaster, plaster gauze, Hydrocal
- Concrete – Sealed concrete, cement board, sidewalk dots
- Plastic – PET sheets, acrylic sheets, polypropylene
- Found objects – Old wood cutoffs, license plates, trays
Look for found objects with texture. Seal porous surfaces like wood or plaster to prevent oil absorption. Metals may require isolation coats.
Using Mediums and Varnishes with Acrylic and Oil
Adding mediums to acrylics and oils can help improve blending and stability:
- Flow improver – decreases surface tension of paints
- Retarder – slows drying time for more flexibility
- Glazing liquid – makes transparent acrylic glazes
- Gesso – helps adhesion and prevents oil absorption
- Linseed stand oil – increases gloss and transparency
- Alkyd mediums – speed up drying time
- Gel mediums – add body and thickness
- Resin oils – increase glossiness
- Gamblin Galkyd – prevents acrylics from absorbing oil
- Golden Acrylic Glazing Liquid – thin glazing coat
- Soft gel – creates texture and prevents sinking in
- Gamblin Gamvar – formulated for oil and acrylic
- Golden Polymer Varnish – safe for mixed media
- Solvent-based oil varnishes – use over oils only
Adding mediums can help improve blendability but test carefully first. Varnishing seals the surface.
Painting Skies and Clouds with Acrylics and Oils
Mixing acrylics and oils allows both speed and blending. This makes painting skies full of depth and movement possible:
- Paint the sky backdrop first with acrylics wet-on-wet. Use blue to violet for distance.
- While still wet, blend in soft clouds by pulling white acrylic through sky colors.
- For drama, glaze transparent oil paints over the dry acrylic sky. Dab in cloud forms.
- Wait until completely dry before detailing cloud edges and adding depth in oils.
- Back-light clouds with thick titanium white oil paint using a palette knife.
- Soften and blend wet oil clouds into the background with soft brushwork.
- Create wispy cirrus clouds by pulling thin white oil paint over blue oils wet-on-wet.
- Use acrylic inks or fluid paints diluted in glazing medium for airbrushed cloud effects.
Combine the blending qualities of oils with the speed of acrylics. Wait for underlayers to fully dry first.
Painting Water and Reflections with Acrylics and Oils
Bodies of water allow creative techniques in both acrylics and oils:
- Make variegated fluid acrylic pours to suggest abstract water
- Layer transparent acrylic glazes and washes for ethereal effects
- Use thick paint with a palette knife for texture in rapids and waves
- Paint reflections wet-on-wet keeping edges soft and diffuse
- Scumble opaquely over acrylics to make disturbed water
- Use a painting knife to mix colors directly for dynamic water
- Glaze multiple layers of oil paint for luminous realism
- Soften hard acrylic edges with subtle oil reflections
- Apply acrylic mottled washes for watercolor-like backgrounds
- Use acrylic pours over collaged elements like maps or letters
- Paint high contrast acrylic reflections then blend softly in oils
- Scrape away dark values for white acrylic foam and waves
Water inspires creativity. Use both the drying benefits of acrylics and blending qualities of oils.
How to Paint Trees and Foliage in Mixed Media
Combining acrylics and oils allows versatility for painting diverse trees and foliage:
- Block in trunk and branch structure in fluid acrylics.
- Paint massed foliage shapes wet-on-wet in acrylics.
- Refine edges and blend colors after drying with oil glazes.
- Use knife techniques in oils to add leaf textures.
- Underpaint pine shapes in green acrylic.
- Switch to small stiff brushes and thin oils to refine needles.
- Scumble light over dark oils to create lacy pine foliage.
- Lay in abstract autumn shapes with acrylics.
- Stipple, glaze, and scumble oils for brilliance.
- Use stiff bristle brushes to scratch trees out of wet paint.
- Apply varied greens wet-on-wet in acrylics.
- Soften edges and build form with thin oil layers.
- Drag a stiff dry brush through paint to create leaves.
Take advantage of each medium’s strengths. Wait for acrylic underlayers to dry fully before detailing in oils.