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Glazing in Oil Painting
Glazing is a thin, transparent layer of oil paint applied over an underpainting. It’s one of the most powerful tools in oil painting because it lets you change the mood, adjust colors, and create a glowing depth that flat paint cannot achieve.
You can glaze with pure transparent colors or with mixes that include white (more opaque). Transparent layers let light shine through, while opaque ones cover more of what’s underneath. Both are useful—what matters is knowing when and how to use them.
A Short History of Glazing
Glazing has been around for centuries. Renaissance and Baroque painters like Jan van Eyck, Titian, and Rembrandt perfected the technique. They often painted a detailed grayscale underpainting (sometimes called a “grisaille”) and then added color through glazes.
Some of these artists built their works with 40–60 layers of glazes. The results were luminous paintings where colors seemed to glow from within. Light would travel through the transparent layers, bounce off the underpainting, and return to the viewer’s eye—creating an effect that mixed paint on the palette simply can’t match.
Glazing also allowed them to adjust colors without starting over. Too bright? A thin dark glaze could tone it down. Too dull? A warm or cool glaze could bring it to life. That flexibility is one reason glazing became such a key part of oil painting tradition.
How to Glaze in Oil Painting
Step 1: Prepare Your Surface
Make sure your underpainting is completely dry before you start glazing. If it’s still wet, the glaze will mix with the paint below instead of sitting transparently on top.
Step 2: Mix Your Medium
The traditional medium for glazing is a 50/50 mix of turpentine and linseed oil. (lately I am using just linseed oil) This makes the paint thinner, smoother, and more transparent. Today, many artists also use modern glazing mediums that dry faster and are less toxic—use what works best for you.
Step 3: Choose Your Brushes
Keep two brushes handy:
- Soft synthetic or sable brush → to apply the glaze smoothly.
- Stiff brush → to blend, soften, or “fade” the glaze into the underpainting because sometimes to glaze does not stick to the paint if that happens to you add more paint than medium and press harder with the brush.
Step 4: Apply the Glaze
- Load a small amount of thinned paint on the soft brush.
- Spread it evenly over the area you want to glaze.
- Use the stiffer brush to feather the edges so it blends naturally.
Step 5: Decide the Purpose
Glazing can be used in two simple but powerful ways:
- Tone down a color → e.g., a cool glaze over a too-bright red to calm it.
- Enhance a color → e.g., a warm glaze over a dull blue to make it glow.
Why Try Glazing?
Even if you don’t use dozens of layers like the Old Masters, a few glazes can transform your painting. They give depth, atmosphere, and subtle color shifts that are impossible to get with just direct paint.
It’s also a technique that connects us to centuries of painting tradition. When you glaze, you’re painting in the footsteps of Rembrandt, Titian, and countless others who discovered the magic of light shining through paint.
So, whether you’re adjusting a single passage or layering for a glowing effect, glazing is a tool worth practicing—it can truly bring your paintings to life.
Excellent Renso, Many thanks for your devoted teachings.
The best and Unique oil, pastels, charcoal acrylics Artist, The best teacher/coach !!!
Renso…this is really helpful because glazing was one area I have not always approached correctly. This is really clear teaching and appreciated. I want to do a grissaile and practice going back into an “Alla prima” art work that may need a bit of adjustment. I enjoyed watching this demo!