A thin protective coating over the finished painting is called a 'seal.' It is colorless in nature and forms a good bond with the paint and surface. To 'varnish' acrylic painting means to add a protective coat or 'seal' to your final artwork. It is a good idea to safeguard your picture for years to come.
A fine finish enhances the colors, giving a professional touch to your paintings and adding a few dollars to the sale cost. Sealed acrylic painting will likely last longer because you're protecting it from dust, dirt, smoke, and a few fading from UV Rays.
Varnishing makes the colors look vibrant because it adds a semi-reflective sheen to the painting. The satin and gloss varnishes add that extra wow factor to the artwork, particularly with dark colors. Each painting is unique. Hence different types of varnish and techniques are required for each painting.
Pros of Varnishing an Acrylic Paintings
Protect against dust - When acrylic paint dries and the water evaporates, the very tiny micropores are left open to collect dust and other particles.
Glossy finish - A permanent gloss sheen on the surface make the painting looks vibrant.
Provides a unified finish - Overall finish is uniform and appealing.
Protection from discoloring - Often, murals and canvas paintings are hung without glass. Even if you wipe the dust from your paintings frequently, some amount of dirt gets trapped on the paint surface, and over time the accumulation can discolor the art.
Must for exterior paintings - Some acrylic colors are sensitive to sunlight, and they fade with time. Hence sealant is an excellent way to protect paintings that are hung outdoors.
Protects against UV rays - When you apply varnish, you cover the painting with another layer to protect from extremes of ultraviolet rays. Quality varnish has UV light Stabilizers. Hence it disperses UV radiation before hitting the painting surface.
Types of Varnish for Acrylic Painting
There are three types of varnish commonly available in the market. You can select between a gloss, satin, or matte finish.
Gloss Varnish generally enhances the colors, giving a permanent enrichment to the colors.
Matte Varnish may soften the colors and do not give any glare.
Satin Varnish is between gloss and matte. Remember, gloss varnishes dry almost 100% transparent.
A matte varnish contains a matting agent, which is usually white, so it is still not 100% transparent even though it dries clear.
Satin and matte varnishes will produce less warmth and even soften the colors. The matte varnish will lighten darker colors. It is also possible to combine these varnish to create a suitable shine that you want, but it will be some experimentation! If you are not happy with the applied varnish, lay a second coat of another varnish and change the look.
Varnish using Brush or Spray?
Best judgement will come when you check the study the surface which needs to be varnished. For smooth surfaces like acrylic and oil paintings, a brush is recommended. It becomes straightforward to use a brush for such surfaces.
For delicate multimedia or textural work, spray varnish will be the best way to go forward. You must first prepare your surface before starting to varnish.
How to apply Varnish using Brush
1. Apply a layer of isolation coat.
2. Before applying the varnish, wipe away any dust from the surface. Use a feather duster or a clean paintbrush to clean away any dust. Make sure it is clean and dry.
3. Lay your painting flat on the horizontal surface in a dust-free room. Ensure that you protect the surface from dripping paint. If you plan to varnish the sides of a canvas, take a small piece of wood to raise the painting. It will prevent the painting from sticking to the surface below.
4. Take a clean flat brush and ensure it's clean. If the brush has any trace of acrylic paint in it, it will come along in the varnish and mix with your painting. Hence complete clean brush is a must.
5. Dip the brush into the liquid and wipe the excess off against the side of the can. Apply long, even strokes to cover the surface top to bottom while moving to the far right of the canvas before working your way down.
6. Examine the surface from a different angle to find areas that aren't moist and glistening to coat them with varnish.
7. Once you apply the varnish and left that spot, do not go back over that area until dry. If you see any area is missed, allow drying completely and then re-varnish.
Always good to apply multiple thin layers of the varnish instead of one thick layer.
How to Apply Spray Varnish
1. Before applying the varnish, wipe away any dust from the surface. Use a feather duster or a clean paintbrush to clean away any dust. Make sure it is clean and dry.
2. Choose a well-ventilated room for spraying.
3. Get in a dust-free room, place your painting vertically on top of a board that is larger than the canvas.
4. Shake the can well for a minute or two to get a good result.
5. Check the spray flow on the practice canvas and go again for real. Apply the spray at a distance of 30-40 cm away from the canvas. It is a natural tendency to move your arm closer to the canvas.
6. Start with the top of the canvas and finish at the bottom, overspray the edge.
7. For little shine and gloss effect, 2-3 layers should be fine, but you can increase to as many layers as you wish to get a different look.
Why Artists do not varnish/seal?A few of the known reasons why artists do not varnish their paintings are because they haven't finished it yet and may want to paint over any time later or do not like the varnish finish.
What's an Isolation Coat?
isolation coat is a translucent coating of a medium that separates
the painted surface from the varnish, and works as a protective layer to
It is irreversible, non-removable, and might cause
modifications to your art attributes. Before applying your varnish, it's
a great idea to use an isolation coat.
How to apply an Isolation Coat?
1. Once the painting is completely dry, clean the dust, if any.
2. Decide what thickness of isolation coat is required for the painting as thickness varies based on the surface of the painting.
3. For textured painting, a thicker coat is required, while a thinner coat will work for flat painting.
4. Take the medium in a container and pour some water if required to get the required consistency.
5. Apply the medium evenly on the entire surface with a brush without leaving any brush strokes mark. Cover the edges completely.
6. Medium will dry in 15-30 mins but do not rush to paint the varnish now. Let it dry overnight, and then apply varnish the next day.
7. Sign your artwork using a clean, small and sharp brush.
Choose a suitable sealant for your Painting
Sealing an acrylic painting can protect precious artwork for years to come. Hence choose the right one, even if it takes some time.
I hope you enjoyed reading the article and have enough information on how to seal your painting with a varnish.