How to glaze an oil painting
Glazing is a technique used to increase the depth and intensify colors in a painting. It can take your work from flat to luminous and glowing.
Simply described, glaze refers to transparent paint that sits on top of opaque paint. It gives the paint beneath it a different effect to the viewer.
Glazes placed on top of dry paint do not physically mix with the colors below. Instead, the glaze tints the paint below it and the colors optically mix to give a beautiful depth of color.
In this post, you will gain a sense of how glaze works, the reasons behind it, and how Evolve students utilize glaze in their paintings!
What is Glaze Paint?
When learning how to glaze an oil painting, students must choose the correct paint. Paints suitable for glazing an oil painting have pigments that tend to be transparent with the addition of medium. Every paint pigment, by nature, becomes transparent, semitransparent, or opaque when mixed with oil.
Now a glaze is simply a suspension of pigment in oil. It has oil or medium with little specks of paint in it. As you build up the amount of oil into the paint, the pigment disperses, causing transparency.
Generally, blacks, blues, purples, and violets tend to appear transparent. Earth colors, like browns, tend to lean semitransparent to opaque, depending on their source. All cadmium and chrome colors, whites, and colors made with white cover opaquely.
Most paint manufacturers will put information on color permanence on each individual tube. Old Holland paint offers their buyers a full online color chart and organizes colors by permanence, from fully transparent to fully opaque.
Once you have settled on a palette of glazes to use, you can begin to work with these transparent paints to elevate your work.
How Glaze Works
In order to glaze an oil painting, you first must have an opaque base. Even if some of the paint allows the canvas to peak through in a vacant shadows technique, everything, even the shade of the canvas, is opaque.
This means that light bounces off the surface of the painting and reflects back to the viewer. This comprises what you see when looking at the painting.
Because glaze paints have dispersed pigment, causing transparency, light is able to permeate glaze paints. Unlike opaque paints, where the light bounces off, the light goes through the glaze.
When the light permeates the glaze, bounces off of the opaque paint, and back through the glaze again to hit your eyes. So the glaze is lit from behind as you look at it, causing a luminosity that is impossible to achieve any other way.
Tips on How to Glaze an Oil Painting
When you do a glaze on top of opaque paint, you are adding color, similar to colorizing a black and white photograph. So we take something that looked monochrome and begin to add color.
Artists must realize that glaze colors will always interact with the medium they become mixed with for fluidity and the opaque paint beneath them. If a linseed oil is used to stretch the paint, it may add a warm tint to the paint. If an artist lays down yellow glaze upon a blue opaque base, the result will appear green as optical mixing occurs.
This optical mixing adds complexity to glazing perhaps more difficult than the actual application of paint. Glazing requires a calculated understanding of what you wish to achieve before you begin to paint. All of your opaque passes must take into account what the glazes will do.
Glazing requires a calculated understanding of what you wish to achieve before you begin to paint.
A layer of alkyd must be placed between opaque paint and the glazes. So once the opaque layers dry, a sealing layer of alkyd will act as an isolating layer, preventing the glazes from sinking into or lifting up the opaque paint. This is also helpful for students, who can wipe the glaze off of the surface as they are learning.
As you mix the glaze, considering the medium will help the painting to succeed. At Evolve, we teach our students to use a 50/50 mixture of linseed oil and alkyd. This mixture enables quick drying without excessive oil. If you use too much linseed oil, the glazes will bead up as you work and increase the drying time, allowing dust to settle into your work. Using alkyd alone will cause the glaze to dry as you work. So a 50/50 mixture of the two gives students a perfect combination.
These technical tips, paired with planning before beginning to glaze, will enable you to create a beautiful luminosity and color in any painting!
Before a student begins to glaze, it is critical that they know where the glaze is needed and have a plan. Of course, as our Evolve students learn we guide them in how to know where the glaze is needed and teach them how to make proper plans.
Once an artist begins to understand where the glaze is needed and the best way to place it without multiple passes, their paintings begin to take on a new life.
Continuous adjustments after the initial application dimish the beauty of the glaze. The paint can be manipulated once it is down, but if you can manage twenty brushstrokes, don’t do twenty-one.
Less is more, particularly in the case of glazing. Once this is embraced, students can begin to use glaze to increase the luminosity and beauty of their paintings.