How to Create a Thick Gloss on Acrylic Paintings

Explore Your Options for a High-Gloss Finish

artist squeezing acrylic paint onto palette
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Acrylic paints are wonderful to work with and it is the medium of choice for many painters. However, acrylics do not have a natural high-gloss sheen and if you want to add a glass-like look to your painting, you will need to take extra steps.

Artists who work with acrylic paints have a few options when it comes to finishing a painting with a glossy finish. Depending on your support, you may want to use an art resin, acrylic medium, or varnish.

Whatever you do, make sure that it was designed for artwork. If you do not, your acrylic painting may discolor or become brittle as it ages.

Whether you are looking to add a high-gloss finish to an entire painting or wish to accent certain portions with a mirror-like shine, you have options. Let's look at some of the possibilities.

Art-Grade Alternatives to Hardware Store Epoxy

It is tempting for artists to make a quick run to the hardware store and pick up an inexpensive epoxy resin designed for DIY projects in the home. When it comes to your artwork, this is not the best idea. It may look fantastic today, but that is going to change over the years. 

Those two-part resins are great for countertops and craft projects, but they are designed to be replaced every 10 or 15 years. Over time, the finish will discolor, turn yellow, or become cloudy, which will ruin the clarity of your painting and all of your hard work will have been in vain.

A better alternative is to use an art-grade resin. These are formulated specifically for artwork to prevent yellowing and often include UV protection. Some can even be used with a top coat of varnish.

ArtResin is a brand that specializes in epoxy resins for creative projects. Their high gloss resin is two-parts and low odor and can be used to create a light coating or a deep surface depending on the effect you are going for.

If you work with hardwood paintings or any alternative surfaces that need a very durable surface, this is a good product to look into.

Use Acrylic Mediums for a High-Gloss Sheen

The downside to resins is that they can be heavy and thick and they are not the best option for every acrylic painting. Acrylic mediums are another option and they can be worked into the paint or used as a top coat. These also tend to be more UV resistant than epoxies, though there can be a color shift that you should be aware of.

  • If you are working on a soft surface like canvas, an acrylic medium may be the best light-weight option.
  • Even if you are painting on hardboard, you may not need (or want) that deep coating epoxies can produce, so a medium would be a good alternative.
  • For a gloss finish in selective areas of a painting, a gloss medium can be mixed into the paints used for that area.

Depending on the acrylic medium that you choose, you can also build up the thickness. It is best to work in thin layers to avoid crazing (small cracks or white lines). You will also need to allow each layer to dry completely before adding the next. With patience, you can build up to a nice, thick layer.

The drawback to acrylic mediums, particularly in thick layers, is that there is more chance for brush or tool strokes.

Experiment with application techniques and try brushing, troweling, or pouring to reduce this.

Choose a Varnish for Your Painting

The majority of acrylic painters will choose to varnish their paintings to protect the artwork. It is a smart move because acrylics are more vulnerable than oil paintings. 

When choosing your varnish, you can choose the finish and this is an easy way to add a gloss coating to your painting. Acrylic varnish is often available in gloss, satin, and matte finishes and these options can be used to your advantage.

For instance, if you have a beautiful lake in your painting, you might choose to varnish that portion with a gloss finish. For a subtle contrast, varnish the remainder of the painting with a satin finish or, if you would like a stark contrast in finish, choose a matte varnish.

It is also important that your varnish is artist-grade quality. Again, hardware store varnishes can discolor your painting and have less UV protection. If you put great effort into your painting, there is no reason to skimp on quality in the final stages.