When working with oils, not all paints behave the same. Some colours cover completely, while others allow light and underlying layers to shine through. This quality is known as opacity.
Oil paints can be opaque, semi-transparent, or transparent, and knowing the difference can transform the way you approach layering, glazing, and colour mixing in your work.
What is Opacity?
Oil paints vary in how much they cover the layers beneath — that’s opacity.
Opaque paints completely cover the surface below.
Transparent paints allow light to pass through, revealing underlayers.
Semi-transparent paints sit in between, offering a balance of coverage and luminosity.
Opaque
Opaque paints offer full coverage in a single layer, making them perfect for backgrounds or solid colour areas.
One example is Art Spectrum Vermilion, a brilliant red pigment with a long history. It was beloved in Ancient Rome, used in illuminated manuscripts of the Middle Ages, and featured in Renaissance paintings.
Opaque paints like Vermilion deliver bold, solid coverage that makes a statement on the canvas.
Semi-Transparent
Semi-transparent paints allow some underlying colour to show through while still providing good coverage. They’re versatile for layering techniques and can create warm, glowing effects.
A classic choice is Art Spectrum Burnt Sienna, a dark, rich brown pigment. This colour is one of the oldest known in art history, popular during the Renaissance for underpainting.
Semi-transparent paints like Burnt Sienna let subtle tones shine through while maintaining depth and body.
See Burnt Sienna in action
Watch our video TESTED: Canvas Panel Boards For Oil Painting! to see Burnt Sienna in use, as Stephen demonstrates our wipe back technique.
Transparent
Transparent paints are ideal for glazing and building luminous depth. By allowing light to pass through, they create glowing effects and rich layers of colour.
Art Spectrum Alizarin Crimson is a cool red with a blueish undertone, well-known for its transparency. It’s perfect for artists looking to glaze and create vibrant, dimensional effects in their work.
Transparent paints like Alizarin Crimson are essential for building radiance and atmosphere on the canvas.
Why Opacity Matters in Oil Painting
Understanding which oils are transparent, semi-transparent, or opaque will greatly help your painting. Oil paints can be used in a few different ways. Some are best for regular painting, some are best for glazing. You will discover each paint has its own superpowers, and with proper use, you will achieve great success.
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