Is The Isolation Coat for Acrylic Painting Necessary?

Is The Isolation Coat for Acrylic Painting Necessary

If you’re an acrylic painter, then you must have carried out several varnishing projects on your painting to seal your work. However, there’s always one step to carry out before varnishing to protect the natural painting surface beneath – isolation coat application. We know this isn’t standard practice among painters, which is why for those who have heard of the technique, one of the most asked questions is “is the isolation coat for acrylic painting necessary?”

I did some research and here is what I’ve found:

Is The Isolation Coat for Acrylic Painting Necessary?

Applying an acrylic coat isn’t necessary before sealing an acrylic painting. But if you want your painting to be easy to clean/restore (i.e. remove and replace varnish) to the same finish as when you made it, you should first apply an isolating layer.

But that’s just a quick snapshot of the question, there’s more to know about it.

So, let’s keep going!

What is an isolation coat for acrylic painting?

An isolation coat is a transparent layer that separates the paintwork from the varnishing. It protects the painting whenever the varnishing is to be removed.

Why is an isolation coat necessary?

An isolation coat creates a sealed coating and protects the paintwork below it from scratching or scraping when the varnishing above it is to be removed or replaced. 

What can I use for isolation coat on acrylic paint?

The Golden Soft Gel Gloss will be perfect as an isolation coat for brush application. It must be the glossy version because they add a whitish matting product in the satin and matte version. 

Isolation coat and varnish for acrylic painting

The isolation layer will help seal the absorbent areas, which will allow for a more even application of the varnish. It’s a bit like laying a thin sheet of glass over the painted surface and then applying varnish to the glass. Meanwhile, the varnishing acts as the sealant for acrylic. But do you need to have both applied?

Do you need to do an isolation coat before varnish?

Applying an isolation coat is a question of need. If you remove the varnishing on the painting, you need an isolation coat. This will help protect the surface if the varnish is ever removed and will facilitate cleaning and future storage to avoid working directly on the pigmented part of the artwork.

Do you have to varnish over an isolation coat?

Yes, after applying the isolation coat, you have to varnish it. The isolation layer cannot perform the function of a varnish. 

How long after isolation coat can you varnish?

An isolation coat will dry in 10 to 30 minutes. However, it would help if you waited for a day to apply the varnishing. 

How do you apply varnish and isolation coats?

To begin with, applying an isolation coating comes first before varnishing and after painting. It can be applied with a brush or spray. Then about 24 hours after the painting, you can apply varnish. 

  1. First, apply a layer of isolation coat on the painting.
  2. Then, once this layer is dry, think about what varnishing is good for the paintwork. You can do a semi-gloss varnish by mixing glossy varnish and matte varnish. 
  3. Some varnishes such as “Liquitex medium and gloss varnish” gloss varnish are very thick. One or two coats will be more than enough if you do not dilute it. 
  4. On the other hand, if you use a liquid varnish or dilute your varnish, 2 to 4 coats should give a good result. If you use a water-based varnish and want to varnish with a sponge, you will need more patience to create your varnish layer by layer. 
  5. Note that the thicker the varnish, the more difficult it is to spread. You can, if necessary, dilute it a little to facilitate the application. In this case, it will take more coats of varnish. 
  6. To varnish with an airbrush, we recommend that you varnish vertically instead. To do this, cross the layers and wait for each layer to dry before applying another; otherwise, you may get messy drips.

How to apply an isolation coat to an acrylic painting?

Below, you’ll find the step-by-step process of applying an isolation coat to a finished acrylic painting using the Golden Soft Gel Gloss Medium. 

What tools you’ll need

  • Golden Soft Gel Gloss
  • Water 
  • Brush or spray 

Step-by-step to apply isolation coat for acrylic painting

  • The Golden Soft Gel Gloss is thick, so we advise that you mix it like this: 
  • Add 2/3 of the Soft Gel Gloss with 1/3 water. 
  • The “Liquitex Medium” and glossy varnish is also perfect. You will then not need to mix it with water unless you want to make it runnier.
  • If you want to use an airbrush, which gives a lovely finish but requires a very well-ventilated place, the Soft Gel Gloss will be too viscous, and it is better to use a 2:1 mixture of “Golden GAC- 500” and “Airbrush Transparent Extender”.
  • For relatively non-absorbent surfaces, as is the case with an even coat of paint, it is recommended to apply one coat by brush or two coats by spray. 
  • For more absorbent surfaces, which tend to be very matt, it is recommended to apply enough insulation layers to achieve a satin sheen on the surface. This may require a minimum of 2 coats applied with a brush or an equivalent minimum of 3 with an airbrush.

There you have your layer of insulation finished. Next, you will have to apply varnish to your acrylic paint.

How to get bubbles out of the isolation coat for acrylic painting?

To get bubbles out, you should mix and stir the isolation coat the night before it’s used. Soft hair brushes will also eliminate bubbles. Finally, by using a spray gun, bubbles will have no way.

How thick is the isolation coat for acrylic painting?

The isolation coat for acrylic painting is usually quite thick, and you’ll need about 1/3 of water to dilute it. 

Tips for applying an isolation coat

  • The best way to get the right texture is by mixing two-part of isolation coats with one part of water. 
  • The surface of your painting must be perfectly clean and of course perfectly dry. Avoid drafts that could deposit dust on your varnish. 
  • The optimal thickness for isolation coats is between 0.5mm and 1.5mm. 
  • Do not coat or varnish in direct sunlight. The coating will dry too quickly and give a porous appearance like embus. It’s hideous!
  • We recommend a relatively flexible and soft brush for applying the coat. 
  • Finally, you must apply the isolation coat with the canvas flat placed on a table.

3 Best Isolation Coat for Acrylic Painting

1. Golden Artist Colors Isolation Coat

Golden Artist Colors makes the best craft paints for artists and hobby painters and their isolation coat is the best on the market. The formulation is ideal for protecting and unifying the paint surface. You can make use of the isolation coat for public painting in the outdoors. 


  • Ideal on painting whose vanishing would be removed 
  • Good for public arts
  • Easy to use 


  • No issue whatsoever

2. Plaid Patricia Nimocks Clear Acrylic Sealer 

This is a clear acrylic sealer that adds shine to your painting surfaces. It’s quick-drying, crystal clear, and doesn’t drip, run over, or yellow. It adds durable protection and shines to your paint objects, giving it a sleek finish. 

The Plaid Patricia Nimocks can be used as an isolation coat and as an acrylic sealer. It’s in a spray can which makes it even easier to use. 


  • Crystal clear after applying 
  • Dries quickly 
  • Ideal for sealing diamond painting
  • Adds shine and sleekness to your painting 


  • Not so durable 

3. Aleene’s 26412 Acrylic Spray Sealer With Gloss Finish

You can make your projects look perfect with Aleene’s Gloss Finish Acrylic Sealer Spray! The durable and versatile sealer ensures a clear, super-gloss finish on interior and exterior surfaces for weather protection. The acrylic formula is a spray-on that can be applied evenly. It dries quickly to a glossy finish. 

It comes in a 6-ounce spray bottle and dries quickly. The adhesive spray can be used on wood, metal, glass, and ceramics. 


  • Super smooth finish
  • Fast drying
  • It can be used indoors and outdoors


  • Sticky after drying

Frequently Asked Questions

Can you use golden soft gel semi-gloss as an isolation coat?

No, the Golden Soft Gel Semi-Gloss should not be used acrylic paint isolation coat. The right product is the Golden Soft Gel Gloss. 

Can you use glazing liquid as an isolation coat for acrylic painting?

Yes, you can. But we recommend using it with the Golden Soft Gel Gloss. Creative painters love this pairing and it works really well.

Can you use a spray isolation coat for acrylic painting?

Yes, spraying the isolation coat is more accessible and can help with bubbles in the medium.  

Final Words

Applying an isolation coat to your painting is not necessary. But if you want extra protection, want the painting to be permanently sealed, and you may want to remove the varnishing, then using an isolation coat is necessary. Some of the best mediums to use for this process include the Golden Soft Gel Gloss and the Golden Isolation Coat. The process can be done with your brush or by spraying. It’s intuitive, and when applied generously, it makes your painting glossy. 

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