How To Seal Acrylic Paint Properly

Painting with acrylic paint is very satisfying. Acrylic paint is very colorful. There are a variety of true colors and bright colors to choose from for your project that aren’t that easy to get with other types of paint and stains. Acrylic paint is quite versatile, you can paint it on almost any surface that you can apply paint to. Moreover, no matter how large or how small the materials is you will paint on, you can paint it with acrylic paint.

You can paint almost any surface with acrylic paint. While wood is a common surface to paint with acrylic paint, you can also use it on materials like ceramic, glass, leather, canvas, or plastic.

However, acrylic paint might not last long on these surfaces by itself without applying a topcoat over it to finish it. Acrylic paint might easily crack, peel off, or scratch easily when left exposed as the only topcoat of your project. This is why it is important to understand how to seal acrylic paint on different surfaces and textures.

This is what the article is all about: How To Seal Acrylic Paint.   

Why Should You Seal Acrylic Paint?

Do you need to seal acrylic paint or not? You should seal acrylic paint in order to protect its color from scratches, from damages, from dust and debris, from peeling off, and from fading too quickly. Although acrylic paint will cling to the surface of wood, for example, the coat it makes is not that tough, scratch-proof, or resistant to wear. You’ll need a more resinous finish to protect it.

Because acrylic paint is more versatile and has more vibrant colors than other types of paint or stain, it is a good medium to use for amateur and hobbyist woodworkers or art craft enthusiasts. It is a water-based paint and is very easy to apply. It is very easy to work with because it is easy to wash off.

Acrylic paint is made up simply of a pigment and an acrylic polymer emulsion. The pigments don’t actually dissolve in the water but are simply floating in tiny particles. When a coat of paint is applied, the tiny particles of pigment attach themselves in an orderly manner to the polymers as the water evaporates. This polymerizes the pigment and spreads it evenly on the surface of the material and creates a layer of paint. This is why it is called self-levelling. 

Because it lacks a resinous binder the paint can easily scratch or chip off after it cures and becomes exposed to air and the environment. It’s important to know how to seal acrylic paint on wood, or other materials of different textures, in order to protect them and give them a lasting finish. Durability is something you want to achieve.

But sealing acrylic paint doesn’t only protect the color of your finished material from damage, it also preserves the wood. Sealing creates a protective finish to protect the wood, at least, from getting wet or absorbing too much moisture. It will protect your project from developing molds and rotting in the future. 

There are different types of protective sealers and varnishes you can use to seal acrylic paint. And these different varnishes are also suitable to different surfaces and textures that you paint acrylic paint on.

Different Types of Varnish Used for Sealing Acrylic Paint

There are two basic formulas of varnish you can use to seal acrylic paint. One is an acrylic polymer, and the other is an acrylic resin. Both are suited for acrylic paint. However, acrylic resin produces a harder and more durable finish because it is made of stronger material. It also produces a shinier and glossier finish. But if you intend to use an acrylic resin varnish, you need to work in a well-ventilated space because of its strong odor. This is because acrylic resin varnish contains some toxic ingredients and uses mineral spirits as solvent.

On the other hand, acrylic polymer varnish is relatively odorless, because it is water-based. It also gives a durable topcoat to acrylic paint and protects it from dust, scratches, peeling off, and other causes of damage. The finish it gives is not as hard and tough as the resinous type. However, acrylic polymer varnish can also give your painted material a glossy finish. 

Acrylic polymer varnish can be wiped off using ammonia solution, in cases when restoration on a material needs to be done. This is one reason why it is advisable to give the last coat of acrylic paint an isolation coat. The isolation coat physically isolates the acrylic paint from its outer varnish. It stands in between the two, so that, when the varnish is being wiped off, the acrylic paint will not be reached by the ammonium solvent. This is in cases when restoration of the material needs to be made, and the varnish topcoat needs to be removed, for example, in restoring acrylic art paintings.

Both acrylic resin and acrylic polymer varnishes can give your material a glossy, a satin, or a matte finish. Depending on how you want your finished material to look. A glossy finish will bring sparkle to your colors. It will give your material asheen that will brightly reflect light and make all shades of color jump out. On the other hand, a matte finish subdues all color. It is also sometimes called a dead flat finish because it makes dark colors darker and light colors flatter. 

However, if your desired finish is something of an old, rustic and country vibe, the fade that a matte finish produces might be desirable. A satin finish produces something in between a glossy and a matte finish. It is glossy, but not too sparkling. It brightens color, but in a subdued way.  

Acrylic resin varnish not only gives you a shinier gloss, but also a tougher and more durable surface. This translates to a longer lasting finish on your paint job. 

How To Bake Painted Ceramic Mugs

One of the materials you can paint acrylic paint on are ceramic mugs. But acrylic paint doesn’t affix to ceramic naturally. It will dry on ceramic, but it will not stay too long unless you bake it or seal it. In order to protect the acrylic paint from scratching or chipping off, you need to know how to bake acrylic paint on ceramic.

Ceramic mugs, vases, and plates are some of the creative art projects that you can work on. You can paint any color pattern or design on these items. And creativity is the only limit to what you can do. However, for these designs and patterns to last, you need to know how to bake acrylic paint onto a ceramic mug, or any material made of ceramic.

The most important item is non-toxic acrylic paint. You need this especially because you would normally use your ceramic mugs or plates for food and drink. You wouldn’t want to eat or drink anything that contains any toxic substances.

You will also need a kitchen oven or a big toaster oven. This is where you will bake and cure your ceramic mug. 

An important thing to remember when you bake acrylic paint on ceramic mugs is to start with a cool oven. You need to put the painted ceramic mug in the oven before turning the heat on. 

The ideal temperature to bake acrylic paint on a ceramic mug is any temperature between 350 – 375 degrees Fahrenheit (150 degrees Celsius). Bake the ceramic mug for at least 30 minutes. Once the timer runs out, leave the painted mug inside the oven until it cools down. This would take about 2 hours or more. Wait for the ceramic mug to be completely cool and dry before taking it out of the oven. Baking in a hot oven will seal the acrylic paint on the ceramic mug. 

How To Seal Acrylic Paint On Ceramic Mug

You can also seal acrylic paint on ceramic mug using a varnish. The best type of varnish to use would probably be a water-based polyurethane varnish. This is a high-quality varnish specifically suited for acrylic paint on ceramic mug.

Water-based polyurethane varnish creates a clear and hard surface on your ceramic mug. This will protect the acrylic paint from dust and scratches, and from easily peeling off as a result of constant handling. It is softer than oil-based polyurethane varnish and therefore easier to apply using either a brush or a spray. Likewise, water-based polyurethane varnish is very easy to work with because you can work with it on the tray for a longer period of time than an oil-based polyurethane varnish. It is also easy to wash off.

How To Seal Acrylic Paint on Plastic

You can use a variety of varnishes to seal acrylic paint on plastic. You can use Polycrylic, a popular brand of sealer used on acrylics, to seal acrylic paint on plastic. It is a combination of polyacrylate and polyurethane and is formulated for use on acrylic paints. Polycrylic is a versatile product especially for beginners because it is easy to spray on. Likewise, it is available in at least 3 different finishes, including glossy, semi-gloss, and matte.

But if you want a tougher and more durable finish, you can use water-based polyurethane, an acrylic polymer varnish, or acrylic resin varnish to seal acrylic paint on plastic. All these can be used to seal acrylic paint on plastic.

However, you need to make sure that your paint is fixed on the plastic surface. Otherwise, no amount of sealing can keep it. But it will peel off sooner or later because the acrylic paint did not stick to the plastic in the first place.

The key is to first create a rough enough surface on the plastic material for the paint to easily adhere to. Because plastic has a smooth surface, the acrylic paint might have nothing to grab on to and might easily slide off once it dries on the plastic surface. Make sure that the acrylic paint is sticking to the plastic surface before applying a protective sealer or varnish on top of it.

But you can also use Mod Podge to seal acrylic paint on plastic. Mod Podge acts as a topcoat for acrylic paint on many surfaces including plastic. It is a clear thin glue that seals the acrylic paint on the plastic surface. One or two coats of Mod Podge will give sufficient protection to the acrylic paint against dust, scratches, and peeling.

How To Seal Acrylic Paint on Wood

You can use most kinds of acrylic varnish to seal acrylic paint on wood. It all depends on the quality of the finish you want to achieve. You can seal acrylic paint on wood using a Polycrylic sealer or a polyurethane varnish.

A Polycrylic sealer is a protective sealer (technically, not a varnish) that is water-based. It is made of polymer structures that are self-levelling and provides an even layer of topcoat on the surface of the wood. It is glossy. 

Polycrylic is easy to work with, compared to polyurethane varnish, because it is water based and easier to apply. Polyurethane varnish is oil-based and has a thicker base than Polycrylic. 

One of the advantages of using Polycrylic sealer is that it doesn’t leave you with a yellowing tint that a polyurethane varnish usually does. The topcoat it creates is clearer. So if you need a clear, glossy topcoat on your material, then Polycrylic sealer is better. 

However, if you want the effect of a little yellowing on your material, or to look more rustic and countryside, then a clear polyurethane varnish will do the job. Because polyurethane varnish leaves an amber shade when it dries. Moreover, a polyurethane varnish provides a tougher exterior topcoat to your material and is more suitable for wooden materials that are often handled or are situated outdoors. 

How To Seal Acrylic Paint on Glass

How to seal acrylic paint on glass is also a challenge. This is because glass is one of the smoothest surfaces you can paint acrylic paint on. However, you can choose either of two ways to do it. One is by baking the paint on the glass, and the other is by applying a finishing layer of varnish on the paint. If you will bake acrylic paint on glass, there are just a few important things you need to remember.

The most important thing to remember is NEVER PUT THE GLASS IN A HOT PRE-HEATED OVEN. This might cause the glass to break due to thermal stress or the sudden change in temperature. It will be such a waste! 

After the paint has dried on the glass material, you need to put it inside the oven while the oven is still turned off. Only after you’ve placed the glass material inside the oven should you turn the oven on. A kitchen oven or toaster oven will do, for small items. This allows the internal structure of the glass to gradually adjust to the increasing temperature inside the oven and not suffer thermal stress.

Set the oven thermometer to around 350 degrees Fahrenheit (175 degrees Celsius). Or on medium heat. Bake the glass material for 30 – 45 minutes at this temperature. You should allow some time for the oven to reach 350 degrees before you start the timer, because the oven was not pre-heated. When the timer runs out, turn off the heat but leave the baked glass material inside the oven for 4 – 8 hours, or until the glass material has completely cooled.

Leave the baked material on a countertop or tabletop for 48 – 72 hours more to allow the paint to cure longer. This seals the acrylic paint on the glass and will protect the paint from peeling off.

Another way to seal acrylic paint on glass is by using an acrylic sealer or varnish. You can choose between pressurized spray-on acrylic sealer or a brush-on type of sealer, like a Mod Podge. The spray-on type leaves on a finer and smoother layer of varnish than the brush-on type. However, both will give you an excellent protective topcoat on your glass material.

You need to work in an open space when using the spray because of the fumes and odors it emits. Likewise, you need to be careful in controlling the layer of sealer when using the spray in order to achieve an even layer on the glass material.

2 – 3 coats of varnish should be enough to protect the acrylic paint on the glass. Just make sure that the previous coat is dry before applying a second coat. It takes about 20 – 30 minutes, sometimes less, before you can apply another coat of sealer. 

How To Seal Acrylic Paint on Shoes

Most water-based acrylic sealers will do the job of sealing acrylic paint on shoes. Regardless of the material the shoes are made of, whether leather, vinyl, or canvas.

However, it is important to note that how to seal acrylic paint on shoes should take into consideration the bending and flexing of shoes. Because shoes are worn and are often in constant motion. Unlike furniture or other materials which remain motionless most of the time, shoes constantly move, bend, and flex with your feet. 

The best way to offset this is by applying very thin layers of sealer on the shoes. Many layers. Because thinner layers are less prone to breaking bonds and cracking due to the irregular movement of the shoes. You can thin out water-based acrylic sealer with water to achieve a thinner varnish. Or if you are using acrylic spray sealer, be careful to apply it with quick passages and not stay too long in one area. Just repeat the process to achieve more layers of protection.

You can also use Mod Podge because its composition is suitable for leather or canvas that shoes are often made of. Mod Podge is a thin glue that would stick to leather or canvas for a long period of time. It also has the ability to stretch a bit and adjust to the flexing of shoes when actively worn.

However, you have the additional option to waterproof your project using a waterproof coat spray. This will add durability and a layer of protection to your shoes against wetness.

How To Seal Acrylic Paint on Canvas

There are two types of varnish you can use on acrylic paint on canvas, and both of them will add durability to your artwork. You can use an acrylic polymer varnish or an acrylic resin varnish. Both work well on canvas.

However, acrylic polymer varnish is easier to work with because it is water-based. It is easier to apply and easier to wash off after use. Moreover, you can apply more coats of acrylic polymer varnish on your canvas material for added layer of protection. This is true especially for canvas shoes, which need many thin layers of varnish for durability. 

But, acrylic resin varnish provides a tougher topcoat than the water-based polymer varnish. This is especially suitable for exterior coats and outdoor material. Acrylic resin varnish is generally oil-based and gives a more durable finish. However, if you want a more durable finish on your canvas material, it is recommended to use an isolation coat before applying the acrylic resin varnish. The isolation coat acts as an interface for the acrylic resin varnish to stick better on the paint and produce a tougher finish.

If you will use acrylic resin varnish you need to work in an open area because it contains some toxic materials, like the fumes and odor of mineral solvents you would not want to inhale. Likewise, you will also need mineral spirits to wash off your brushes after use.

There are many projects you can paint on canvas with acrylic paint. Art paintings in general are painted on canvas. You have bags, shoes, and some materials of clothing made of canvas. Choose the acrylic varnish that would suit your project, whether the polymer or the resin type.

Moreover, there are many other surfaces and textures you can paint with acrylic paint, like plastic, wood, ceramic, glass, and shoes. This is how versatile acrylic paint is. But you need to know how to seal acrylic paint on these surfaces to achieve a more durable and lasting finish.