What Are Glazes in Painting?

Hello everyone, today I suggest we take a look at a fascinating and sometimes mysterious painting technique: glazing. With its effects of transparency and light, it has been used by many master painters of the past, but it is just as useful in our modern practices, whether with oil, acrylic, or even watercolor. You will see that with a few simple basics, it is entirely possible to create effective and beautiful glazes.

Grab your brushes, let's get started!

What is a glaze?

A glaze is a thin layer of transparent or semi-transparent paint that is applied over a dry surface that has already been painted. The idea is not to cover what is underneath, but to subtly modify it: like a colored veil that enriches the light and changes the hue, while still enabling the initial artwork to be seen.

Glazes are not just an "effect": they have real uses in painting.

- Adding depth: by adding transparent layers, colors seem to become more vibrante and intense.
- Modifying an existing shade: instead of repainting, you can subtly adjust the color (soften a shadow, warm up a complexion, cool a sky...).
- Creating light effects: certain reflections can only be achieved with the transparency of a glaze.
- Harmonize the painting as a whole: a light veil applied on an area helps to unify the contrasts or create a consistent colored atmosphere.

(Without glaze on the left vs with glaze on the right)

Glaze characteristics

Transparency

The glaze works as a colored veil. To achieve this effect, the paint must be diluted with a suitable medium:

- Oil-based → linseed oil, Flemish medium, siccative medium…
- Acrylic → transparent acrylic medium, glossy or matte gel.
- Watercolor → just water.

The more fluid the paint is, the more it reveals the layers underneath. However, be careful: over-diluting can weaken the color and give a "washed out" effect. Balance is therefore important: translucent, but still colorful.

Thinness

A glaze must be a light and thin layer, almost as if you were caressing the surface with the brush.

If you apply too much paint, it will become opaque and hide the layer underneath, which defeats the purpose.
To apply correctly, use a soft brush (such as a spalter or cat tongue) and work with a small amount of material.
The ideal is to apply several thin glazes rather than one that is too heavy: this allows for subtle and luminous nuances.

The left layer is too opaque

Dryness

This is undoubtedly the most important rule. Each layer must be perfectly dry before applying another one.

If the previous layer is not dry, the next glaze will mix with it instead of laying on top. Result: a blurred and dull color.

The drying time depends on the medium:

- With oil, sometimes you have to wait several days.
- With acrylic, a few hours is enough.
- In watercolor, just a few minutes.

This step requires patience, but it is what ensures the transparency and brightness of the final result.

5 tips for successful glazing

Adjust the texture to your medium

Regardless of the technique used, whether it be oil, acrylic, gouache, or watercolor, the success of a glaze depends greatly on the texture of the paint. Seek a balance: the mixture should be fluid, but not so liquid that it runs or loses intensity.

If the material is too thick (far left), the glaze will become opaque; if it is too diluted (far right), it will lack body. The paint should glide smoothly under the brush, leaving an even and transparent veil. Here the perfect texture would be the second from the left.

Work with little paint

When starting out, we often tend to load our brush too much. Glazing requires the opposite: it is better to pick up a small amount of highly diluted paint. You can always add more if necessary, but removing excess material is much more complicated.

Layer thinly

A single thick glaze will not give the same result as the superposition of several thin layers. Each veil brings its own shade, its own brightness. Three light glazes, one on top of the other, often create a much richer and more subtle effect than a single too forceful pass.

It is this layered transparency that gives the works of the old masters their incomparable depth. There is another undeniable advantage, by working slowly we are less likely to make mistakes.

Test before you start

Do not take the risk of damaging a part of your painting that you already like. Before applying a glaze over a large area, always test it on a small, inconspicuous corner or on a separate sheet. This way you can check the dilution, transparency, and hue, and adjust your mix if necessary. This habit will save you many disappointments.

Arm yourself with patience

Drying is the key to a beautiful glaze. If you're in a hurry and apply the next layer too quickly, you risk blurring the colors and losing all transparency.

On the other hand, by allowing each step to dry properly, your glazes will lay perfectly on top of one another, like colored filters that enrich the light. It's a time-consuming technique, but it is precisely this time that gives the glaze its magic.

With a few precise strokes, good layer management, and some experimentation, glazing becomes a magical tool for enriching your artworks. Whether you paint with oil, acrylic, or watercolor, don't be afraid to take your time and layer the veils of color.

It is through this slow construction that depth, subtlety, and that unique luminosity arise, which make up all the charm of the glaze. So don't wait any longer to enrich your artworks! 😊

Writer and illustrator: Chloé Pouteau