How to Prep a Canvas Before Acrylic or Oil Painting
Feeling inspired and ready to paint your canvas? It might be tempting to put your brush right to work, but you may need to prep a canvas before you begin. To keep your oil or acrylic paintings looking their best for years to come, priming your surface is the first step!
Every artist has their own way of prepping their canvas. Usually sizing, priming, and underpaintings are involved in the process. The quality of your work is based on a good foundation so it’s important to take your time and use the proper materials to make your artwork last! In this guide, we will answer the basic questions about prepping your canvas for oil and acrylic painting.
What is priming?
Priming is the process of creating a barrier between the canvas and the paint. It’s typically done by applying layers of acrylic gesso, clear acrylic medium, or oil primer. Prepping your canvas makes it less absorbent, helps your paint sit better on the surface, and protects your canvas from natural corrosion. The primer gives you an even ground to work with, which means your brush strokes can flow easier and you will end up using less paint!
A primer is especially important when it comes to oil painting because it makes the colors stand out more and prevents dull patches in your finished work.
Is there a difference between priming for acrylic painting and priming for oil?
Yes! Acrylic gesso is technically suitable for priming both oil and acrylic paint. However, we recommend using a solvent-based oil painting primer like Maimeri Oil Primer.
Oil paint doesn’t adhere to gesso well and it will affect the longevity of your painting. In time, the gesso will pull the oil out of your pigments and make the paint look dull.
Check out Artist Kelly Baskin’s tutorial for prepping her canvases for oil painting using Maimeri’s Oil Primer.
How do you apply gesso or oil primer?
You can use the same steps for acrylic gesso or oil primer. Here is the process that we recommend:
- Stir the container very well before using. This is important! So don’t skip it.
- Decide whether you're going to apply one or a few coats of gesso/primer. One coat will give you a rougher finish and two coats will provide a good overall finish.
- For gesso, if you are applying several coats, dilute the gesso of the first coat with a little bit of water to a thickness of heavy cream. Different brands of gesso have different viscosities, so you’ll have to experiment! You may need to add more or less water depending on the brand of gesso that you use.
- Using a clean, Princeton Gesso Brush or Catalyst Wedge apply the gesso/primer directly to the stretched canvas in even strokes. Work from the top to the bottom of the canvas, in parallel strokes. And don’t forget the edges!
- Let the first layer dry for a few hours before moving onto your second layer.
- In the meantime, wash your brush immediately with soap and water. If you let the gesso dry on the brush, it won’t come out. (This is why we love using a Catalyst Wedge instead for easy clean up.)
- After the first layer is dried, you can sand it lightly with fine sandpaper for a smoother surface.
- If you are applying two coats, apply the second coat in the direction perpendicular to the first coat. This coat can be thicker than the first coat.
- Let the coat dry, and sand again if you want a super smooth surface.
- Finally, clean your brushes.
Optional: Add additional layers for more smoothness.
Kelly Baskin likes using a Catalyst Wedge no. 1 to apply her oil primer. It’s easier to wipe a Catalyst tool clean (it also requires no solvent) than it is to get oil primer out of a paint brush. Using a wedge also allows you to fill in any texture on the canvas, leaving you with a smoother surface.
You can watch Kelly’s tutorial here for applying oil primer with a Catalyst Wedge.
How long do you need to wait before painting?
It can be tempting to start painting after a few hours if the primer or gesso feels dry to the touch. We recommend waiting at least 24 hours before painting for the best results.
What is the difference between sizing and priming?
Sizing is the method of sealing the surface and forming a barrier layer between the canvas, and the primer and paint layers. When a layer of sizing is applied, it decreases the absorbency of the primer.
If you’re stretching your own canvas and using oil painting primer, you need to size your canvas with rabbit skin glue (or synthetic alternative) first to seal the surface. But most store-bought canvases are ready to prime.
Priming on the other hand is done to create an even surface to paint on. Acrylic gesso offers more tooth (coarseness/grip) for the paint to hold onto, while oil primer offers a smoother surface.
What if I don’t want to prep the canvas?
If you don’t want to worry about priming your canvas, you can buy pre-primed canvases like the Strathmore 300 Series Stretched Canvas. They are 100% cotton and triple-primed, so you don’t have to do any prepping with them. You can find them in traditional and gallery profiles.
Canvas panels are another great option if you’re just getting started with oil or acrylic painting or want a practice surface. They are made of stretched and triple primed 100% cotton canvas, adhered to a stiff backing.
What is underpainting?
Underpainting is not the same thing as priming. It is the first thin layer of paint applied after priming. It is typically a tonal rendering of your final painting that gives you a base to work out your composition and values. A lot of artists find it easier to start with the tonal values and contrast than just a bright white canvas.
You can use a range of color palettes for your underpaintings. For example, imprimatura uses earth tones like umber and sienna. The goal of an underpainting is to unite the color values of your overall painting and add a tonal dominance. If you use a yellow-toned underpainting for a landscape scene it will make the painting seem warmer.