I love the look of a high gloss finish on an acrylic painting. The colors are richer and the end result looks more like an oil painting. Once one of my acrylics is varnished, I can’t tell the difference between my oils and acrylics!
I do this in two steps. I’ve found that the paint on varnish I like so much has a tendency to smudge perfectly dry paint. Part of this is because I use water to mix my acrylics so they are going to be less adhesive than straight paint. For those gasping “OMG I heard you shouldn’t use water with acrylics”, check out this video –
Ok, now that we have that out of the way, what do we do about it? Well first I use a spray acrylic coating by Krylon (amazon affiliate link). This is a matte finish, UV-Resistant clear spray. I apply a very light coat of this, then let it dry for a few hours…or a few days because more often than not I forget about it while it’s outdoors drying. This stuff has a very strong odor so don’t use it inside! Make sure to shake the can very VERY well. Hold the can about a foot away from your art (I hold it farther because I only need a light coating for my purposes). Don’t use it when it’s humid, very hot or very cold outside.
Once I remember to go bring the artwork back inside, I move onto the last step, Liquitex Gloss Varnish. I apply this with a sponge brush for even coverage. Once the first layer dries (at least 3 hours), I apply a second coat.
Before you varnish your paintings, make sure you have all the photos you will need for prints. It is a HUGE pain to get a good photo of artwork that has a high gloss on it because of the glare.
I really need to point out that I am not using these products as intended. I strongly encourage you to test this on a small project before you do so on one of your larger masterpieces. I would hate for there to be a variable in the way you paint or the supplies you use that would make it so that the combo I’m using would not work out well for you.