How To Finish An Acrylic Painting: Easy Guide

Can you put a finish on an acrylic painting? Yes, you absolutely can, and it’s a crucial step for both protection and enhancing its appearance. Finishing techniques acrylics is about more than just making your artwork look good; it’s about protecting acrylic paintings from dust, UV light, and environmental damage. This guide will walk you through everything you need to know to achieve a professional and lasting finish for your acrylic creations.

Acrylic paints, once dry, form a flexible plastic film. While this is durable, it’s not impervious to scratches or fading over time. Applying a protective layer is like giving your artwork a shield. This layer, often referred to as acrylic varnish, can also dramatically alter the final look of your painting, offering options from a subtle sheen to a high-gloss brilliance.

Why Finishing Your Acrylic Painting Matters

Finishing an acrylic painting is vital for several reasons. It’s the capstone to your creative effort, ensuring your hard work is preserved.

Preserving Your Artwork

Over time, paintings can be affected by various environmental factors.

Dust and Grime: These can settle on the surface, dulling colors and requiring gentle cleaning that might risk damaging the paint layer if not properly protected.
UV Light: Sunlight and even artificial light can cause colors to fade. A varnish with UV inhibitors acts as a barrier against this damage.
Scratches and Abrasion: The flexible acrylic film, while somewhat resistant, can still be scratched. A tough varnish layer provides a buffer.
Moisture: While acrylics are water-resistant when dry, prolonged exposure to moisture or humidity can still affect the paint film and the substrate.

Enhancing Visual Appeal

Beyond protection, a finish can significantly impact how your painting is perceived.

Color Saturation: Some varnishes, especially gloss finishes, can deepen and saturate colors, making them appear more vibrant and luminous.
Uniformity: A consistent finish across the entire painting eliminates the uneven sheen that can occur with different paint thicknesses or mediums. This creates a more cohesive and professional look.
Surface Texture: Different finishes offer different tactile and visual textures, allowing you to control the final appearance. A matte finish acrylic will subdue any inherent sheen from the paint, while a gloss finish acrylic will amplify it.

Choosing the Right Finishing Product

The world of acrylic finishes can seem vast, but it boils down to a few key types of products. Selecting the correct one depends on your desired aesthetic and the level of protection you need.

Types of Acrylic Finishes

Acrylic Varnish: This is the most common and versatile option. It’s a liquid that dries to a clear, protective film. Varnishes come in various finishes.
Acrylic Mediums: While primarily used during the painting process to alter paint consistency, texture, and sheen, some mediums can also be used as a final coat. However, they may not offer the same level of protection as a dedicated varnish.
Acrylic Glazes: These are typically thin, transparent layers used to modify color or create subtle effects. While not a primary protective finish, a final acrylic glaze can add depth and a uniform sheen.

Finish Types: Matte vs. Gloss vs. Satin

The most significant decision you’ll make is the type of finish.

Gloss Finish Acrylic:
- Pros: Deepens colors, enhances vibrancy, creates a luminous, reflective surface, easy to clean.
- Cons: Can show glare and reflections, may highlight surface imperfections, can sometimes make colors appear darker.
- Best For: Paintings where you want maximum color saturation and a high-end, reflective look. Often favored for portraits or still lifes.
Matte Finish Acrylic:
- Pros: Subdues reflections, offers a velvety, non-glare appearance, ideal for achieving a look similar to traditional oils or watercolors, hides brushstrokes and surface texture.
- Cons: Can sometimes “flatten” colors or make them appear slightly desaturated, less resistant to smudging and dirt compared to gloss.
- Best For: Works where you want to emphasize the painted surface itself, avoid distracting reflections, or achieve a soft, subtle look. Landscapes and abstract art often suit this finish.
Satin Finish Acrylic:
- Pros: A balance between gloss and matte, offering a soft sheen that enhances colors without excessive glare.
- Cons: Less dramatic than gloss, not as glare-free as matte.
- Best For: A versatile choice that provides a pleasing sheen and good protection for most types of acrylic paintings.

Product Forms: Brush-On vs. Spray

You’ll also encounter finishes in liquid (brush-on) and aerosol (spray) forms.

Brush-On:
- Pros: Allows for more control over application, can be worked into textured surfaces, generally more economical for larger areas.
- Cons: Risk of brushstrokes if not applied evenly, requires a clean brush and careful application to avoid dust.
- Application: Best applied with a soft, wide brush in thin, even coats.
Spray Varnish Acrylic:
- Pros: Creates a very smooth, even coat, ideal for textured surfaces or when you want to avoid brushstrokes, quick drying time.
- Cons: Requires good ventilation and protection for surrounding areas, can be more expensive, risk of uneven coverage or “splotches” if not applied correctly.
- Application: Best applied in thin, cross-hatching coats from a consistent distance.

Prepping Your Acrylic Painting for Finishing

Before you apply any varnish, proper preparation is key. This ensures the finish adheres well and provides the best possible protection.

Ensuring the Paint is Fully Dry

Acrylics can feel dry to the touch quickly, but the paint film continues to cure for a longer period.

Drying Time: Generally, acrylic paint needs to be completely dry and cured before varnishing. This can take anywhere from 24 hours for thin layers to several weeks for very thick impasto applications.
Why it Matters: Applying varnish to “tacky” paint can cause the varnish to adhere poorly, wrinkle, or even lift the paint.

Cleaning the Surface

Dust and debris on the painting’s surface will be sealed under the varnish, becoming permanent.

Methods:
- Soft Brush: A clean, soft-bristled brush (like a fan brush or a large, soft natural bristle brush) is excellent for dusting off loose particles.
- Lint-Free Cloth: A slightly damp (with distilled water, if necessary, and allowed to dry completely) lint-free cloth can gently wipe away grime. Test this on a small, inconspicuous area first.
- Compressed Air: Can be useful for blowing away dust without touching the surface.

Priming the Surface (for certain applications)

While not always necessary for a painted surface, if you’re applying a very heavy or glossy finish that might soak into unpainted areas (like the edges of a canvas), a light coat of acrylic primer or a diluted varnish can create a more uniform surface.

Applying Acrylic Varnish: Step-by-Step

Applying varnish is a methodical process. Rushing can lead to mistakes that are difficult to correct.

Step 1: Test Your Varnish

It’s always wise to test your chosen varnish on a scrap piece of painted canvas or paper that matches the surface and paint you’ve used for your main artwork. This helps you:

See how the finish affects your colors.
Practice your application technique.
Ensure the varnish dries clear and without issues.

Step 2: Gather Your Supplies

Having everything ready beforehand will make the process smoother.

Chosen Acrylic Varnish (spray or brush-on)
Soft, wide brush (if using brush-on)
Clean, dry palette or container for pouring varnish
Gloves (optional, but recommended for sprays)
Masking tape (to protect edges if needed)
Drop cloth or old newspaper to protect your workspace
Well-ventilated area

Step 3: Apply the First Coat

This is where you start sealing acrylic paint.

For Brush-On Varnish:

Pour: Pour a small amount of varnish onto your palette or into a clean container.
Load Brush: Dip your clean, soft brush into the varnish. Don’t overload it.
Apply: Start at one edge of the painting and brush the varnish on in long, even strokes.
Overlap: Overlap each stroke by about half to ensure complete coverage and avoid streaks.
Direction: Try to work in one consistent direction for the entire coat (e.g., from top to bottom).
Thin Coats: It’s better to apply several thin coats than one thick coat. This prevents drips and uneven drying.
Remove Excess: Carefully check for any drips or thick spots and gently smooth them out with your brush.

For Spray Varnish Acrylic:

Ventilation: Ensure you are in a well-ventilated area. Open windows or work outdoors.
Protect: Cover your workspace and any surrounding objects. Wear gloves and a mask if recommended by the product.
Shake: Shake the can thoroughly as instructed on the label.
Distance: Hold the can about 10-12 inches away from the painting.
Motion: Apply in a steady, sweeping motion, moving from side to side or top to bottom.
Cross-Hatching: Apply the first coat in one direction, then allow it to become tacky (usually a few minutes), and apply a second coat in the perpendicular direction. This ensures even coverage.
Thin Coats: Again, multiple thin coats are better than one heavy coat.

Step 4: Drying Between Coats

Allow each coat of varnish to dry completely according to the manufacturer’s instructions. This usually takes at least 30 minutes to an hour, but can be longer depending on humidity and temperature.

Step 5: Applying Subsequent Coats

Once the first coat is dry, inspect it for any missed spots or imperfections.

Light Sanding (Optional): For a perfectly smooth finish, some artists lightly sand between coats with very fine-grit sandpaper (e.g., 400-600 grit) or a fine synthetic scrubbing pad. This removes any dust nibs and creates a slightly rougher surface for the next coat to adhere to. Wipe away dust thoroughly after sanding.
Repeat: Apply additional thin coats as needed, allowing them to dry between applications. For most paintings, two to three thin coats are sufficient for good protection.

Step 6: The Final Coat

This is your final coat acrylic that seals everything in and gives your painting its definitive look. Apply it with the same care and attention as the previous coats.

Brush-On: Ensure even strokes and smooth out any potential drips.
Spray: Make sure your cross-hatching pattern is consistent for a flawless finish.

Special Considerations and Techniques

Some situations require a slightly different approach to finishing.

Varnishing Textured Paintings (Impasto)

For paintings with thick paint application (impasto), getting an even varnish coat can be tricky.

Spray Varnish is Often Best: Spray varnishes are excellent for textured surfaces as they can reach into crevices without pooling.
Brush-On for Textured Surfaces: If using a brush-on varnish, use a soft, natural bristle brush and gently dab or stipple the varnish into the paint layers to ensure all surfaces are covered without flattening the texture too much. You may need more coats.
Mediums: Mixing a bit of acrylic medium into your varnish can improve its flow and help it get into textured areas.

Using Acrylic Mediums as a Finish

Certain acrylic mediums can be used as a protective finish, though they might not offer the same UV protection or durability as dedicated varnishes.

Gel Mediums: Some clear gel mediums, when applied thinly and evenly, can provide a protective layer and alter the surface sheen.
Finishing Mediums: Products specifically marketed as “finishing mediums” can be applied as a final coat. Always check the product label to ensure it’s suitable for use as a topcoat.
Diluting: You can sometimes dilute acrylic mediums with water to create a thinner, glaze-like finish. However, too much water can affect the medium’s binding properties.

Applying an Acrylic Glaze for Color or Sheen

An acrylic glaze can be used as the very last step after varnishing, or as the final protective coat if a very light finish is desired.

Purpose: To subtly alter the overall color tone or add a slight sheen.
Application: Mix a small amount of transparent acrylic color or a clear glazing medium with a glazing liquid or water. Apply thinly with a soft brush. Work quickly and blend edges to avoid hard lines.
Multiple Layers: Build up the color or sheen slowly with multiple thin layers.

Using an Isolation Coat

An isolation coat is a clear layer of acrylic medium applied before the final varnish.

What it is: A flexible, transparent layer of acrylic medium (often a soft gel or fluid medium) that acts as a barrier between the paint and the varnish.
Why use it: It protects the actual paint layer from being damaged by harsh solvents that might be present in some spray varnishes, or if you ever need to remove the varnish for cleaning or re-varnishing in the future.
Application: Apply one or two thin, even coats of acrylic medium and let it dry completely before applying your final varnish.

Maintaining Your Finished Acrylic Painting

Once your artwork is beautifully finished, a little care will ensure it lasts for generations.

Cleaning

Regular Dusting: Gently dust your painting regularly with a soft, dry brush or a clean microfiber cloth.
Deeper Cleaning: For stubborn dirt, you can use a slightly damp (with distilled water) lint-free cloth. Wipe gently from the center outwards. Avoid rubbing.
Avoid Harsh Chemicals: Never use household cleaners, solvents, or abrasive materials on your finished acrylic painting.

Displaying Your Artwork

Avoid Direct Sunlight: While varnishes offer UV protection, prolonged direct sunlight will eventually cause fading. Display your artwork away from direct sun exposure.
Manage Humidity: Extreme fluctuations in humidity can stress the painting and its substrate. Aim for a stable indoor environment.
Framing: Framing your artwork behind glass (especially UV-protective glass) offers an additional layer of protection against dust, grime, and potential physical damage. Ensure there is a small gap between the painting surface and the glass.

Troubleshooting Common Finishing Issues

Even with careful application, sometimes things don’t go perfectly.

Yellowing Varnish

Cause: Older varnishes, or those not formulated for archival quality, can yellow over time. Some non-archival spray varnishes can also yellow if applied too thickly or if they contain inferior binders.
Solution: Use high-quality, artist-grade varnishes specifically designed for acrylics. If a painting has yellowed significantly, it might be necessary to carefully remove the old varnish and re-varnish.

Streaks or Brushstrokes

Cause: Uneven application with a brush, using too much varnish on the brush, or not overlapping strokes adequately.
Solution: Apply varnish in thin, even coats. Use a good quality, soft brush. For spray varnishes, maintain a consistent distance and speed. If the streaks are minor and the varnish is fully dry, a very light sanding with fine-grit paper followed by another thin coat may help.

Uneven Sheen (Dry Spots)

Cause: Not covering the entire surface, or the varnish was too thin in some areas.
Solution: Ensure complete coverage with each coat. For brush-on, overlap your strokes generously. For spray, use a cross-hatching technique.

Fogging or Cloudiness

Cause: This often happens when varnish is applied to a surface that is not completely dry, or if there is high humidity. Moisture gets trapped in the varnish film as it dries.
Solution: Ensure your painting is thoroughly dry. Apply varnish in a dry environment with good air circulation. If fogging occurs, it might be possible to remove the varnish with the appropriate solvent (check varnish manufacturer’s recommendations) and reapply.

Cracking or Peeling

Cause: Applying varnish to a dirty surface, applying a second coat before the first is sufficiently dry and adhered, or using incompatible products.
Solution: Proper surface preparation and adequate drying time between coats are essential.

Frequently Asked Questions (FAQ)

Q1: When can I varnish my acrylic painting?
A1: Your acrylic painting should be completely dry and cured before varnishing. This typically means waiting at least 24 hours for thin layers and several weeks for very thick impasto paintings.

Q2: Can I use oil paint varnish on acrylic paintings?
A2: It is not recommended. Oil paint varnishes often contain solvents that can be too harsh for acrylic paint and may cause damage or discoloration. Always use varnishes specifically designed for acrylics.

Q3: How many coats of varnish should I apply?
A3: Typically, two to three thin coats are sufficient for good protection and an even finish. Some artists may apply more for added durability or a specific visual effect, but always allow each coat to dry completely.

Q4: What is the difference between matte and gloss acrylic varnish?
A4: Gloss varnish creates a shiny, reflective surface that deepens colors and enhances vibrancy. Matte varnish creates a flat, non-reflective surface that reduces glare and gives a more subdued look.

Q5: Can I remove acrylic varnish?
A5: Yes, most acrylic varnishes can be removed using specific solvents recommended by the varnish manufacturer. This is often done to clean the painting or to re-varnish it. It’s advisable to test the removal process on a small, inconspicuous area first.

Q6: Does spray varnish offer the same protection as brush-on?
A6: Yes, both spray and brush-on varnishes, when applied correctly and made by reputable brands, offer comparable protection. The choice between them often comes down to personal preference and the type of surface you are varnishing.

Q7: Will varnish change the colors of my painting?
A7: Varnishes can subtly alter the appearance of colors. Gloss varnishes tend to make colors appear richer and slightly darker. Matte varnishes can sometimes make colors look a bit lighter or less saturated. It’s always best to test your varnish on a scrap piece of your artwork first.

Finishing your acrylic paintings is a rewarding step that elevates your work from a simple creation to a durable piece of art. By following these steps and choosing the right products, you can ensure your paintings look their best and are protected for years to come.