Painting over an already colored canvas can seem daunting, but with the right preparation and techniques, you can successfully paint over any color canvas. When painting over dark colors especially, understanding how to properly prepare the canvas and use techniques like underpainting can help you achieve vibrant, evenly coated results.
In this comprehensive guide, we’ll walk through everything you need to know to paint over an already colored canvas, step-by-step.
Assessing the Current Canvas Color
The first step is to assess the current color of your canvas. Is it a light color like white or off-white? A medium tone like beige or gray? Or a darker shade like black, navy or crimson?
The darkness or lightness of the base color will impact the prep work required, as darker colors usually need more conditioning to cover fully. Lighter canvas colors are typically easier to paint over.
Also note the finish of the canvas – is it matte, satiny, glossy? The shinier the original finish, the more prep work it may need to create an effective painting surface.
Preparing the Canvas Surface
Once you know the base color and finish of your canvas, you can move on to preparation.
If the canvas has a glossy coating, lightly sanding can help rough up the slick surface so paint adheres better. Use fine grit sandpaper (at least 220 grit) and gently sand the entire canvas surface.
Priming the canvas is highly recommended, especially if painting over a dark color. Primers help paint adhere evenly to the canvas. For oil or acrylic painting, use an acrylic gesso primer that dries quickly. Apply 2-3 thin, even coats allowing drying in between coats.
For medium to dark canvas colors, apply a color corrector as your primer coat. Mix white acrylic paint into the gesso to lighten it up before applying to the canvas. This helps neutralize the existing color so your paint colors apply true. The lighter the primer coat, the better.
Underpainting is key when working on a colored canvas. Underpainting blocks out the existing color so it doesn’t mix with or dull your paint layers.
Here are two underpainting approaches:
For this method, choose an underpainting color lighter than your final color but in the same color family. For example, paint a thin pinkish layer before applying red paint. The underpainting peaks through giving depth, while preventing the red from getting muddy.
This technique involves first painting your entire image in a gray monochrome. You can mix black and white paint, or use a neutral gray color. Grisaille underpainting is extremely effective for blocking out any distracting canvas color.
Paint Application Techniques
When painting over colored canvas, alter your paint application technique to ensure opaque, evenly coated color.
Use Palette Knives
Applying thick passages of paint with a painting knife helps cover better than thin brushstrokes. Use a knife to block in larger areas of color.
Apply Multiple Layers
Don’t expect to cover in one coat. Apply two to three layers of each color, allowing drying time between each layer. The repetition builds to a rich, opaque finish.
Add painting medium like gel, emulsion or glaze to your acrylics before applying to increase transparency and flow. This enhances coverage across the textured canvas.
Finish with Varnish
Once the painting is complete, seal it with two coats of matte varnish. This saturates the color and creates an evenly coated surface.
Tips for Painting Over Specific Canvas Colors
The general techniques above work for prepping and painting over any color canvas. Here are some additional tips for specific colors:
– White is easy to paint over with minimal prep
– No need to prime white canvas before painting
– Underpainting optional for lighter colors
– Prime with 3+ coats of white gesso to block out black
– Use a very light gray or white grisaille underpainting
– Build up colors with thick, opaque layers
– Lightly sand glossy canvas first
– Underpaint with complementary green to neutralize red
– Deep colors may require higher opacity paints like acrylic
– Prime with white gesso to cover blue canvas
– Underpaint with orange undertones before painting blues
– Overlap brushstrokes and use palette knife to fill in
|Original Canvas Color
|– No priming needed
|– Regular thin layers
|– Prime with 3+ white gesso coats
|– Light gray or white
|– Thick, opaque layers
|– Lightly sand first
|– Complementary green
|– Higher opacity paints
|– Prime with white gesso
|– Orange undertones
|– Overlapping strokes, palette knife
Frequently Asked Questions
Here are answers to some common questions about painting over colored canvas:
Should I always prime before painting over canvas?
Priming is highly recommended, especially when painting over darker colors. For white or very light canvases, you may be able to get away without priming. In general, priming creates the best surface for painting over any existing color.
Can I use white gesso to prime if I’m not painting white?
Yes, white gesso is effective for priming and blocking out the canvas color even if you are painting with colors other than white. The white primer neutralizes the canvas so your paint colors apply accurately.
How many coats of primer and paint are needed?
Apply 2-3 thin coats of primer, allowing drying time between each coat. For the paint, expect to use 2-3 layers of each color as well, slowly building up opacity. Using multiple thin layers prevents dripping and uneven coverage.
Should I varnish my painting on colored canvas?
Varnishing is highly recommended as a final step when painting on colored canvas. The varnish seals the paint and canvas surface, saturates the colors, and gives an evenly coated, glossy or matte finish depending on the varnish used.
Painting over an existing colored canvas opens up many possibilities for giving paintings a unique, creative background. With the right prep work and painting techniques, you can transform even the darkest canvas into a vibrant new work of art. Use a step-by-step process – assess the canvas, properly prepare the surface, underpaint to block out the base color, and apply paint in opaque layers. And don’t forget to seal the finished piece with a protective varnish! With some planning and patience, you can paint over any color canvas with beautiful results.