Glazes seem to be a mysterious thing to many. I’m going to blow the lid off of them right here and now.
There are a couple of ways to mix a glaze. The idea is to give some transparency to your paint. So you can do it with water. The problem with adding too much water to acrylics is that it thins the adhesion (aka gluing) power of your paint. I try to never go more than 50/50 water and paint. Water allows you to get some really neat effects that you can’t get with other methods of glazing. It lets the paint get really runny. I like that in some areas.
Another method is to use glaze medium. Glaze medium has a runny consistency, pours well, dries clear and is essentially the binder in acrylic paint. It’s great stuff. Liquitex makes a great glaze medium as does golden. Golden has 2 finishes, gloss and satin. While I’m a liquitex paint fan, I’m a fan of Golden’s mediums, mainly because it does come in satin. Adding glazing medium to your paint will make it both translucent and glossy. You can add as much glaze medium to your paint as you want it will dry and it retains its ability to stick to the canvas and previous layers. You can also then add water to your glaze.
You can also use matte medium and gel medium as a base for your glaze. These have a thicker consistency than glaze medium. These work well if you want to work impasto or just wish to have your brush strokes be more visible.
Different paints have different tinting strengths. You’ve probably noticed this as you paint. Some colors you have to put heavier coats and more coats to cover the previous layers. Some colors will cover over any other color with a single thin brush stroke. This will affect how much paint you mix with your medium to make a glaze. With most of my colors I start with a 50/50 mix of paint to medium. I mix it thoroughly and then test it on a spot on my pallet. If I think it’s too opaque I add more medium. There is no scientific mixture to demystify how much paint to add, just get a scrap of paper or a spot on your pallet to test things. If you really want to go thin start with 75% glaze and 25% paint. You can always add a touch more paint, or another layer of glaze.
The great thing about glaze is that you can build up layer after layer of color and get a mix of colors or just the final darkness you’re seeking. The thin layers of glaze also allow light to filter through. The old masters used it to build up layers of paint that seemed to glow. And the reality is they did in a way. Each thin layer of glaze reflected light through the paint. You can also use pure color in glazes that overlay each other. They will mix visually to create a different color.
Glaze medium and other mediums tend to dry faster than pure paints. You can add what is called retarder to the mix, or more water. But Be aware that occasionally when you go to reach for you glaze you may find it dried out on your pallet!
You can also buy pre-mixed glazes, but where is the fun in that?