Author’s Note: This article was originally published on BrushThralls.com under the title “Glaze Medium”. I’m reposting it here for sake of completeness and to clean up a few issues the original had. New comments and additions will be in italics.
Glaze Medium – What Is It?
I see this question quite a bit on various painting forums, along with “I bought some Glaze Medium, now what?” I thought I would try to shed some light on this subject.
The Term Glaze
I’ll start by defining what a glaze is in painting terms. Simply put, a glaze is a thin (mostly) transparent layer of paint (or ink). The official definition is: A transparent coating applied over a painted surface to modify the color tones underneath. That sounds a bit more complicated than it really is.
When a transparent color is applied over another, the top color alters the first. This is because light rays mix, creating a visual color mixture. You can achieve greater depth in your painting by using several layers of transparent color. In glaze paint layers, light rays penetrate the layers, strike the opaque model surface and reflect back to the eye creating various visual color mixes. The more layers of pigment that the light travels through, the greater the “depth” of color the eye perceives. Confused yet?
I could go into a long dissertation on light theory and the visual spectrum, but I’ll skip that and go to a simpler example. Almost everyone has seen “3D” glasses with one red film lens and the other blue film lens. When a movie or video is separated into slightly different channels using red & blue, the lenses filter out the other channel and make things appear “3D” to your brain. Looking at it without the glasses just gives you a splitting headache. If you look at a yellow object with the blue lens, it will appear green. The same yellow object will appear orange through the red lens. Glazes work the same way. They help to filter the light reflected from an object into a different color spectrum. Take a look at the following diagram:
Using the red lens example above, the stripe on the far left is a yellow object. The next stripe is that same yellow object with a thin red glaze over the top of it. It now has an orange hue. Each stripe after the first is another glaze layer on top. The solid red stripe on the far right is an opaque version of the color used in the glaze. Bored yet? Me too. Let’s get to the good stuff.
