You’ve just painted a masterpiece and you want it to last forever. How can you ensure that the colors will stay vivid and the surface will survive any wear and tear over the years? One way to ensure this is to seal acrylic painting with a varnish.
How do I seal acrylic painting?
Best to seal acrylic painting is using a varnish. You can use Acrylic Polimer or Resin varnish available in different dinishes. Pick a finish to match your artwork look and end goals. Decide if you want to apply it with brush or spray. When done, wait at least 2 weeks for you artwork to be completely dry.
If you want all the details in depth about how to make the perfect plan for sealing your acrylic artwork, dive in. This article contains all the basic information you need and beyond to make the best choice for you and your piece.
Should You Seal Acrylic Painting?
The first step in the process of preserving the integrity of your artwork is to decide whether sealing your acrylic painting is necessary.
Common concerns about applying varnish include the difficulty of the process, the uncertainty about the outcome, and ignorance concerning which type of varnish to use.
The benefits of sealing your acrylic painting outweigh the drawbacks in many cases.
Benefits sealing acrylic paint are:
- improve the final look of the painting
- deepen the colors
- protect the work
- make it easier to clean in the future.
What Do You Use to Seal an Acrylic Painting?
The best sealant for an acrylic painting is varnish. Traditionally, varnish was made from natural materials and acted as a cover on paintings that was meant to be removed. (Think of the plastic film that comes on your brand-new TV screen).
The varnish began to show signs of aging, it was removed and reapplied, revealing the original, preserved colors beneath.
As science has developed, permanent varnishes made from synthetic materials have become more common.
When Should I Varnish My Acrylic Painting?
The varnishing process cannot begin until the painting is completely dry. Although the outer layer may feel dry a few hours after being painted, the paint is often still wet underneath. Most acrylic paintings should be completely dry after one week, but some artists wait longer just to be sure.
Things like the thickness of the paint; the other mediums used; and the humidity, temperature, and airflow in the room all affect drying time.
Which Type of Varnish Should I Use?
There are two main types of varnish available: acrylic polymer varnish and acrylic resin varnish. Be sure to choose one with UVLS (Ultra Violet Light Stabilizers) to protect your painting from discoloration due to UV rays.
Acrylic Polymer Varnish
This varnish is non-toxic and water soluble. This means that you don’t have to worry about having good ventilation while applying it, and you can easily clean your tools afterwards.
*NOTE* Polymer varnishes must be thinned with water according to the manufacturer’s guidelines before use.
Pros compared to Resin Varnish
- Is a bit easier to work with,
- easier to clean up
- safer to use.
Cons compared to Resin Varnish
- is not as strong as resin
- it can be difficult to apply evenly since it dries so quickly.
Acrylic Resin Varnish
This varnish is glossier, stronger, and clearer than its polymer counterpart. Resins are typically flexible and provide a slightly higher-quality result.
*NOTE* This varnish needs to be thinned with mineral spirits before use, so be sure to apply it in a well-ventilated area.
You will also need the mineral spirits to clean your tools.
Because the resin doesn’t dry as fast as the polymer, it often does a better job of self-leveling over the surface of the painting.
Add Isolation Coat before applying Varnish
It is important to consider applying an isolation coat to your painting before you add the varnish.
This is a glossy, protective layer that separates your varnish from the painting underneath. It can provide a level of extra protection to your painting and help even out the absorbency of the piece.
TIP: If you use a removeable varnish, it is best to apply an isolation coat before you apply the varnish.
Which Type of Finish Should I Use?
There are three main types of acrylic seal finishes; Glossy, Matte and Satin
Glossy finish will be the most reflective and provide the deepest color saturation. Depending on where the painting will be displayed, a glossy finish might be too reflective and distracting.
This finish also highlights any texture in the painting, which can be a good thing or a bad thing depending on your desired aesthetic. Glossy finish is also great when priming wood for acrylic painting. The primer will stick better to glossy varnish than any other.
Matte finish is the least reflective, but it can lighten the darker colors of the painting.
Satin is a good compromise between the characteristics of both glossy and matte finishes.
TIP: If you are not sure which finish is best for you, you can begin with gloss and add a matte coat later on. You can always add satin or matte finishes on top of a gloss varnish, but once you apply a matte varnish, you can’t achieve the same level of gloss again.
How to Seal Acrylic Painting?
Let’s find out exact steps on how to finish acrylic painting:
Step 1: Choose Your Method
You can apply your varnish one of two main ways.
- The first option is to brush on your varnish. This allows for more control in the application, and it is the easiest approach.
- The second option is to use a spray-on varnish. This will give a more even finish to the surface, but it requires more ventilation.
*NOTE* No matter how you apply your varnish, you should do it in a horizontal position where possible. Applying varnish to a vertical painting increases the risk of dripping and uneven drying.
Step 2: Prepare the Space and Materials
Before you begin to apply your varnish (and optional isolation coat), make sure you have the right space and materials for the job.
- The location should be well-ventilated (especially if you use a resin varnish)
- Temperature should ideally be between 60-90 degrees Fahrenheit (15-32 degrees Celsius).
- The area should not be very dusty, and
- You should clean the surface of the painting with a soft brush or lint-free cloth before you begin.
After preparing the space, collect your materials.
If using liquid varnish, a broad synthetic-hair brush should be adequate. If using spray, all you need is the spray can.
TIP: You may also need small pieces of wood to evenly prop up your painting and prevent it from sticking to the surface of the table you are using. A backing of foam or cardboard can prevent pooling in the center of the canvas.
Step 2: Test Run
Before you begin, check that the varnish is compatible with your painting by varnishing a test piece. This can be a small piece of canvas with the same paint and colors you used on the actual painting.
TIP: Apply the (optional isolation coat) and varnish to the test piece and ensure your desired aesthetic.
Step 3: Apply
Mix your isolation liquid with the manufacturer’s recommended ratio of water in a shallow container.
* NOTE* If using an isolation coat, be sure to apply this quickly. Start in the middle and work your way closer to the edges to prevent drips. Give the isolation coat at least 24 hours to dry before applying your varnish.
When you are ready, mix your varnish with the recommended ratio of water (for polymer varnish) or mineral spirits (for resin varnish). Apply your varnish following the same instructions for the isolation coat.
TIP: Even out the brush strokes as much as possible before the varnish begins to dry.
See how Mely uses spray varnish in Video below:
I love to use Krylon Brand. Didn’t have any problems with them yet.
Step 4: Dry
Allow the varnish to dry for at least two weeks before you transport or display it. You can rest it against a wall with the painted side closest to the wall to protect it from dust and other impurities while dying.
Ones it dries, your acrylic artwork will last for years to come!
Can you use Modge Podge to seal an acrylic painting?
Modge Podge could technically be used to seal a painting since it dries clear, but it is not made for this purpose. Using a product specifically made to protect acrylic paintings is the best option for the long-term health of your artwork.
Can I use hairspray to seal acrylic paint?
Hairspray cannot adequately seal an acrylic painting as it has none of the benefits of a professional varnish (UV protection, color preservation, durability).
How many coats of varnish should you put on an acrylic painting?
This is completely up to the artist’s taste. It is best to use multiple thin coats rather than one thick coat if you prefer thicker coverage. Let the varnish dry 3-6 hours between each coat.