Is Acrylic Paint Waterproof? Learn How To Do It

Complete beginners and professional artists use acrylic paint for their creations. Acrylic paint is one of the most resourceful types of paint, allowing you to create beautiful creations with the stroke of a brush. Thanks to its quick-drying qualities and low price, acrylic is one of the most popular options.

One common question constantly asked about it is whether it’s waterproof or not. In this guide, we’ll cover everything you want to know including, whether it’s waterproof, how to make acrylic paint waterproof so it doesn’t run off(spoiler), and the benefits of waterproofing it. 

acrylic paint waterproof

Is Acrylic Paint Waterproof?

Acrylic paint is not waterproof and will absorb water when wet. Since it's water-based, it can wash off before the paint dries. While dry acrylic paint is slightly water-resistant, it isn't completely impervious to moisture. To make acrylic last, you must seal it to prevent water damage and so it doesn’t wash off.

It's important to note that water-resistant differs from waterproof. A water-resistant object will resist water penetration to some extent. However, it will still absorb water in some instances, like prolonged exposure to wet conditions.

A waterproof object can remain completely dry no matter the length of exposure to water and moisture. You can make your acrylic paint waterproof by applying varnish or sealant.

How Does Acrylic Paint Work?

To understand why it’s not waterproof and how you can make acrylic paint waterproof, it’s essential to learn how it works. Acrylic paint results from the mixture of pigment (color) and acrylic polymer emulsion. The presence of emulsion in acrylic makes the paint dry quickly. There are other ways you can make it dry even quicker as well.

Acrylic paint comprises three main ingredients:

  • Acrylic resin keeps the paint on the wall and ensures that your paint doesn't crack when it dries. Resin, also known as binder, keeps the pigment in place and creates a binding effect during the drying process.
  • Pigment refers to the color in acrylic paint. A pigment is a collection of tiny granular particles that remain suspended in the paint. A tint can come in different forms: natural, synthetic, organic, and inorganic.
  • Water is the agent responsible for creating water-based acrylic. The process is simple. You mix the resin (binder) with pigment (coloring) in water and get a fluid water based paint.
acrylic paint drying

Why You Should Waterproof Acrylic Paint

It’s easy to fall for the myth of acrylic's waterproof quality. Hence, you might think that acrylic can remain in good condition without some effort at coating it.

This is a big mistake.

Acrylic paint might be water-resistant, but it’s not waterproof. It's water-based paint, which makes it prone to thinning if it comes into contact with water and can possibly wash off.

If you use acrylic as exterior paint, raindrops can ruin the paintwork. Your acrylic painting is not always safe indoors either since an accidental spill can destroy your art piece. There is a good reason why most art class instructors that teach acrylic painting will tell you to waterproof it before it dries.

Acrylic soaks in water when in a wet state, which is why you need to seal it before it dries. The paint can develop some resistance to water after its completely dry, but this doesn't mean it'll completely safeguard the paint against water damage in the future.

How To Make Acrylic Paint Waterproof

Waterproofing acrylic preserves your work and ensures it’s well protected. The most common method of waterproofing acrylic is coating it with varnish.

Varnish is a glossy material that gets applied to acrylic to create a waterproof seal. Varnish comprises four different materials — oil, resin, drier, and solvent.

Varnishing acrylic locks in the paint and prevents water from affecting it. Varnish also has anti-fade properties that keep your acrylic vibrant even under prolonged exposure to light. When you finished painting, don't forget about applying varnish — a matte and satin varnish will also get the job done.

Here is how you can varnish acrylic paint in different situations and achieve an acrylic gloss:

acrylic paint

On Canvas

You've painted a Picasso-worthy scene on canvas. You need to waterproof it, so your work doesn't get washed away by rain or freak spills.

Buy some polymer varnish and simply apply it to your canvas painting. This will create a water-resistant film and protect your piece from getting drenched. For reference, there is also spray varnish you can use to make things much more straightforward. 

On Glass

Waterproofing acrylic glass items are more challenging but doable. There are two common methods to waterproof acrylic paint on glass:

Oven Baking: Set your acrylic glass painting in the oven and turn the temperature switch to 350°F. Leave it to bake for 30-45 minutes and avoid baking beyond the time limit.

Although 30-45 minutes is the ideal range, the number can vary. Check the product label to get the exact guidelines on drying time.

Air Drying: Oven baking your acrylic shortens the time it takes significantly. But, it’s not ideal in all situations since it creates harmful fumes. Plus, you need to clean the oven when it finishes drying.

That's why sometimes air drying and applying varnish is a better option. It's a simple procedure:

  1. Varnish the acrylic glass
  2. Place the paint in an airy room or open location
  3. Let it dry for three weeks

With air drying, you won't have the same speedy drying process since it slows it down, but you're free from handling fumes and cleaning ovens. And you can dry it in the sun to speed things up after adding varnish to the glass's surface.

On Clay

While this varies depending on the clay, the process is the exact same as it is for canvas. Simply apply the sealer on the clay a few times, let it dry, and you're good to go. You can use this method to seal acrylic paint on polymer clay and even sculpting clay.

On Wood

The easiest way to waterproof acrylic paint on wood is to varnish it. However, your wood painting is going to need multiple coats if you want it completely protected. Try to wait a few hours after you apply the first coat before you apply the next one.

On Metal

Metal is the perfect material for acrylic, and you can paint doorknobs, picture frames, lamps, and other metallic objects with it. Unlike wood, waterproofing acrylic paint on metal doesn't require multiple coats of varnish. On average, metal acrylic paints typically only require one coating of varnish to seal adequately.

On Plastic

You can paint plastic with acrylic to create wonderful artsy items. However, keep in mind that your little plastic-painting project will use more paint than average.

There's no difference with waterproofing acrylic on plastic. A coat of varnish should seal the acrylic and keep the paint in place.

On MDF and Masonite

Medium-Density Fibreboard (MDF) and masonite are both special types of wood used in home construction. You might want to give your MDF or masonite items a makeover by painting them with this paint. 

Thanks to their smooth surfaces, MDF and masonite need just 1-2 applications of varnish to become waterproof. To make it better, consider priming the surface with gesso before you paint. Priming usually prepares the surface better and holds the paint together.

Frequently Asked Questions (FAQs)

What do I need to apply varnish?

Coating your acrylic paintings with varnish doesn't require special tools. A regular paintbrush will do for applying it on acrylic painted surfaces. You should use a poly brush since it can absorb the varnish and distributes the substance evenly across the painting surface.

Will varnish make acrylic waterproof?

Varnishing is a guaranteed method of making acrylic waterproof. The materials in varnish (driers, repellents, etc.) are notable for their waterproofing abilities, which are perfect for your needs.

Should I prime before varnishing?

The general advice is to prime your canvas, or any other artistic medium, before painting and varnishing. Primed surfaces are less susceptible to the breakdown of paint and thinning of varnish.

Is acrylic paint waterproof after it dries?

Dried acrylic paint has more water resistance compared to wet paint. However, air-drying your acrylic won't make it waterproof in an instant. Exposing it to moisture — whether indoors or outdoors will get it wet.