Do you have a plastic object that you want to give a new look? Painting it with acrylic paint is a great way to do it. It’s a relatively easy process that can be done with a few simple supplies.
Today, I will walk you through the entire process step-by-step How to paint acrylic on plastic surfaces?
Why Acrylics Work Well on Plastic
Acrylic paints are a great choice for plastic because:
- They form a flexible paint film as they dry, preventing cracking or peeling.
- Acrylics bond well to slick surfaces like plastic when adequately prepared.
- They can be built up in thin layers to create depth and dimension.
- Acrylic’s quick drying time allows you to work quickly( 10-30 mins for a thin layer) when layering.
- With a protective sealant, acrylic paints are durable on plastic.
Step 1 – Thoroughly Clean the Plastic Surface
Proper surface preparation is crucial for successful acrylic painting on plastic. Plastic’s smooth, non-porous nature means paint does not adhere well without some tooth for gripping.
That’s why starting with an absolutely clean surface free of dirt, dust, oils or debris is critical. Here’s how:
- Scrub the plastic with warm water and dish soap using a soft brush or sponge.
- Completely rinse away all soap residue under running water.
- Allow the plastic to dry before moving to the next step.
Step 2 – Lightly Sand the Plastic
Once clean and dry, the plastic needs a bit of “tooth” added to give the paint something to grip. Lightly sanding does the trick:
- Use 220 grit or higher sandpaper. Anything more coarse may leave deep scratches.
- Gently rub the sandpaper over all areas to be painted.
- Try rubbing in circular motions to create a uniformly scratched surface.
- Wipe away all dust with a dry cloth after sanding.
Sanding prepares the slick plastic for accepting acrylic paint.
Enhancing Adhesion with Mediums
Apply an acrylic matte or gel medium before the primer for even more excellent paint adhesion on the plastic. These mediums act like glue between the plastic and paint. They dry transparent and help the paint stick tightly. Squeeze a small mound of gel or matte medium directly onto the sanded plastic surface and spread evenly with a soft brush. Allow to dry, then apply the primer over the dried medium.
Step 3 – Apply a Primer Coat to the Surface
Priming the plastic provides another layer for paint to grab onto.
- Use a spray primer made of plastic for quick, even coverage.
Water-based primers designed for plastic work best. Work in thin, even coats, allowing proper drying time between coats.
- Alternately, brush on a thin layer of gesso evenly over the surface.
After the primer has cured, apply a smooth layer of acrylic gesso over the primed plastic with a brush. Allow to dry completely. For best results, apply 2-3 coats of gesso, lightly sanding between each layer to remove brush strokes or bumps. This creates the ideal, slightly textured surface for acrylic paint to adhere to.
- Allow the primer to dry thoroughly before painting for at least 24 hours.
Allow the primer to fully cure as directed on the label, usually 24 hours. Then, lightly sand again with fine sandpaper to create a smooth painting surface. Proper priming prevents paint from peeling or chipping later on.
- Lightly sand again with fine sandpaper to smooth the primed plastic.
Step 4 – Paint in Thin, Even Layers
Now, the surface is ready for acrylic paint. Remember to use thin layers:
- Apply paint opaquely but not too thickly. Thin layers are better than one thick coat.
- Allow each layer to dry thoroughly before adding the next, usually 15-30 minutes.
- Start by evenly covering the surface with an underpainting layer.
- Slowly build color, depth and details over the underpainting in subsequent layers.
- Mist with water or use a retarder to prevent paint from drying too fast.
Thin layers prevent wet paint from getting muddy or peeling.
Step 5 – Smooth and Soften Paint Between Layers
For blending acrylics on plastic:
- Allow paint to dry before smoothing to avoid lifting paint.
- Lightly sand to remove any brush marks and create a smooth surface after each layer.
- Use a damp brush or soft cloth to gently smooth and blend colors after drying.
- Apply gel medium over dry paint then rub with a brush for softened effects.
Blending creates gradual shifts between colors rather than hard edges.
Step 6 – Highlight and Shade to Add Dimension
Depth and shadows make a painting pop. Here’s how to achieve that with acrylics on plastic:
- Allow your base colors to dry fully before detailing them.
- Mix a small amount of white acrylic into a color to create highlight tones. Apply to raised or curved areas.
- Add a touch of black or complementary color to a base hue to make shadows. Brush into crevices.
- Soften highlighted and shaded areas by smoothing color transitions with a damp brush.
Highlights and shadows add realistic dimension to acrylic paintings on plastic.
Step 7 – Varnish the Painting for Protection
The final step is applying an acrylic varnish or sealant:
- Allow paint to cure fully before sealing, around 72 hours.
- Use an archival acrylic varnish with UV protection for best preservation on plastic.
- Apply in thin, even coats allowing proper drying time between layers.
- Two to three light coats give the best protection for your acrylic painting.
How to Seal Acrylic Paint on Plastic Surface
Once the acrylic painting is complete, protect it by applying an acrylic sealer or varnish. This seals the paint and protects against scratches, moisture, UV rays and other environmental factors. Use an archival-quality acrylic sealer in a matte, satin, or gloss finish.
Check out my article about how to seal acrylic paint
Spray sealers allow for smooth, even application. Apply in thin layers following the directions on the label and allow proper drying time between coats. Sealing is essential for giving your painted plastic art longevity and durability.
Tips for Avoiding Common Acrylic Painting Mistakes
Watch out for these common pitfalls when working with acrylics on plastic:
Issue: Paint peeling or flaking off
Fix: Allow proper drying time between thin layers and don’t rework areas after drying.
Issue: Brushstrokes showing through painted finish
Fix: Use soft synthetic brushes and sand between paint layers. Keep paint consistency smooth but not too thin.
Issue: Colors getting muddy
Fix: Avoid over-blending. Allow previous layers to dry thoroughly before adding a new color.
Issue: Paint drying too quickly
Fix: Mist layers with water to slow drying. Use retarding mediums. Keep a wet palette.
How long will acrylic paint last on plastic?
With proper surface preparation, high-quality paints, and a protective acrylic sealer, acrylic paint can last many years on plastic without chipping, peeling or fading. The key is allowing paint to cure before sealing and maintaining the painted piece properly.
Can you paint acrylic onto plastic?
Yes, you can paint acrylics directly onto plastic surfaces. However, plastic’s non-porous, slick surface requires priming first to aid paint adhesion. Lightly sanding provides tooth for the paint to grip as well. Following proper prep steps allows acrylics to bond tightly and lastingly on plastics.
Do you need to prime plastic before painting?
Yes! Priming before painting plastic is highly recommended. Acrylic primers create a uniform painted surface and prevent paint peeling or chipping issues down the road. Primers designed for plastic provide superior adhesion. Alternatively, you can use gesso to prime and prepare the plastic for painting.
What type of paint can be used on acrylic plastic?
Acrylic paints are the best for adhering to and lasting on acrylic plastic surfaces. When dry, acrylics form a flexible film that adheres well to slick, non-porous plastics. Craft and artist acrylics work well on acrylic plastic with proper prep and sealing.
What paint will stick to plastic?
The paints that best stick to plastic surfaces are:
- Acrylic paints
- Enamel paints
- Industrial “plastic” paints
- Certain spray paints formulated for plastics
With proper sanding and priming, these paint types can bond tightly and permanently to plastics.
Will acrylic paint stick to plastic?
Yes, acrylic paint will bond well to plastic surfaces. Lightly sanding provides tooth for adhesion. Priming gives acrylics an additional layer to grip. Allowing acrylics 72 hours to cure before recoating or sealing maximizes adhesion.
You must have been practicing!