What is a glaze
Glazing is an amazing method to create all kinds of painting effects, resolve painting issues, illuminate color and create layering. It is a number one tool for painters and has been used throughout painting history. Glazing is still used today as a main technique for styles from realism to abstraction, and also used with most mediums including oil, acrylic and watercolor.
A simple definition of a glaze is – a transparent color, or application of a transparent layer of color onto a painting. This simple explanation can be deceiving as there is much to be said about glazing. In this article I offer a variety of ways to use and create glazes for painting purposes.
When and how to use glazes
A glaze is often applied to a painting while it is still in process, to shift whatever colors are already there. It can be applied very subtly to just slightly shift an underlying color, or more strongly to dramatically change underlying colors. In general though, it is usually used OVER a previously applied and dry, layer of one or more colors.
As an example, let’s say you are painting a realistic portrait for a client oor commission. After months of hard work the portrait looks good enough to show to your client for approval. Your client, however, thinks the flesh tones are too yellow and wants you to fix it. What do you do? Argue with the client? Not a good idea. Return to your studio and repaint the entire face again? Also not a good idea.
An easier solution is to apply a glaze over the flesh tones that will somewhat diminish the overall yellow. By using purple, which is the opposite of yellow, in a VERY transparent layer this will be easily and quickly resolved.
How to make a glaze
Let’s continue using the above scenario – the portrait of a face that turned out too yellow. To reduce or “tone down” the yellow color, apply a very transparent purple glaze over it. To make the glaze mixture, start with any type of nonporous surface as a palette to mix your glaze color
On your palette of choice, squeeze out about a tablespoon of a clear medium (more or less depending on the size of the job at hand). Use the appropriate medium. In other words, if working in oil use an oil medium, for encaustic (wax) use wax, and for acrylic use an acrylic medium. From here on, I will instruct as if for acrylic, in which case any gloss acrylic medium will be fine. Acrylic mediums will appear white when wet, but dry clear.
Also add to your palette, next to but not too close, to the medium already there, a small amount of a purple paint color (I like to use Dioxazine Purple) in a 1:10 ratio – 1 part paint to 10 parts medium. Mix it really well with a knife so it’s all homogenized. Mixing it with a knife instead of a brush will result in a well mixed color, making it easier to apply an even subtle layer of the purple glaze.
To apply acrylic evenly without streaks, we need to slow down the drying time, to give us more time to brush it out smoothly before it dries. Oil painters don’t need to do this step because oil is already slow drying enough to easily apply an even glaze.
For our acrylic mixture, there are several options to slow down the drying of our glaze mixture. (1) add up to 15% retarder to the glaze mixture. (2) Instead of using a regular acrylic medium, substitute a slow drying medium (like the one by Golden called Acrylic Glazing Liquid). This medium already contains 15% retarder to 85% acrylic gloss medium. (3) Use a slow drying acrylic paint. I like to use Golden’s slow drying line of acrylics called OPEN. With OPEN use the OPEN medium along with OPEN paint colors for your glaze.
Once you have made your mixture more slow drying, pick up a small amount of the mixture, using a smooth flat wash brush. Apply it thinly to your surface to obtain an evenly applied transparent layer of color. If getting a smooth application with a brush is difficult for you, use a soft lint free rag instead of the brush.
Glazes vs Washes
First lets distinquish between two very different types of transparent painting layers you can apply – glazes and washes. These are different, yet often mistaken for the same thing.
The term “glaze” refers to a transparent layer made with a mixture using substantial amouts of a clear medium, along with small amounts of paint color. A “wash” is a transparent layer made instead with a mixture of substantial amounts of water along with small amounts of paint color.
For washes I almost always use modern colors instead of mineral colors. However, for glazes I use both types of colors. Let me explain.
If a glaze will be very subtle and transparent, then the mixture will use very little paint mixed into a lot of medium. In this case it doesn’t matter which type of paint you use – modern or mineral – because there is so little paint color in the mixture.
If a glaze color will be more intense, then add more paint color into the mixture along with the medium. In this case using a modern color will add more intense color while a mineral will add less.
Key Glazing Tips
Use enough medium. The amount of medium you use makes a big difference. Use enough medium in your glaze mixture to make it transparent. It can be subtle to shift the underlying layer a small amount, or more opaque overlaying a more intense color coverage.
Use the right order when making mixtures. Always START with the medium on your palette, then add very small amounts of paint into it. If you do the reverse – starting with the paint color, and then adding medium into the paint – the mixture may remain stubbornly opaque causing you to go through large quantities of medium to get it transparent enough to your liking.
Fixing a glaze that is too opaque. If your painting becomes too opaque in feel because you covered the underlying layers too heavily, you can sand off some of the upper paint layers once they are dry. Work by hand with pieces of waterproof sandpaper (I like grit 220) and lots of water. For large areas or heavy layers use an electric sander.
Best color intensity is achieved by using a gloss medium instead of a matte for your glaze mixtures. If you use any medium that is satin, semi-gloss or matte, then the product will contain a matte powder – a white powder that creates the matte sheen. This will definitely change the color of your glaze.
Don’t overbrush a glaze. If you overbrush a glaze mixture, in other words continue brushing while the glaze starts to dry and is tacky, it will create a “dirty” appearance. The glaze won’t appear smooth, but will gunk up and look badly applied.
Be frugal adding water. Adding too much water to your glaze mixture, over 15%, can create a hybrid wash-glaze. Washes use water as I mentioned before, while glazes rely more on mediums. Water can decrease the gloss of the glaze and therfore decrease the color intensity.
Reduce lint if using a rag. If you use a rag to apply your glaze, and it is not lint-free, then small particles of the rag may get onto your surface causing a cloudy effect.
Ideas for mixing palettes
- A sheet of glass
- A palette pad (pads you can purchase made of gray or white sheets of coated paper)
- disposable plastic plates (you can keep and reuse once the paint has dried)
- sheets of freezer paper (not wax paper or parchment paper) taped to a table or piece of wood
- shellac coated wood available in art stores as traditional painting palettes
Example of a Glazing Technique
Adding a vignette to a painting, is a good example to see where glazing can come in handy. For the painting pictured here, I want to darken the top edge of the sky area, and also close to the two side edges. This is called a vignette technique. A vignette uses a subtle darkening of the edges, closing in the image a bit. This will make the sky feel cozier, more contained and not as expansive.
Dip a brush or rag (pictured here) into the medium first, picking up about ¼ teaspoon of the medium, then dip the same rag with the medium into a small amount of one or more of the paint colors. Both medium and paint will be on your rag or brush simultaneously but not mixed together. Now you can see why I call it a dirty mix glaze.
Work in small areas while the paint is still wet. Switch to a clean brush or dry rag to remove some of the excess glaze to allow this newly applied glaze color to subtly blend into the image. As you finish one area, move along the edge using different combinations of color every 1″ – 2″ (25 – 51 mm). Avoid using the same color too frequently or applying the color too opaquely with not enough medium.