Starting with a well-prepared canvas is one of the most important steps in oil painting. To ensure a successful result, you need to begin with a durable surface that supports the paint and enhances the longevity of the artwork. Preparing a canvas with traditional sizing and oil ground can seem complicated, but if you use the right materials and techniques, you’ll be ready with a reliable, stable and archival ground that is optimal for oil painting. Here’s how to do it!
Step 1: Tack Down the Canvas
Begin by temporarily tacking your canvas to a sturdy surface or work table. You’ll want the canvas to lie flat to ensure that you can apply the sizing and ground evenly and smoothly. This setup also allows the canvas to dry evenly and prevents warping. Use a staple gun or tacks to secure the canvas edges, stretching it lightly to ensure it lies as flat as possible. You don’t need to worry about achieving perfect tension here—this step is just to hold the canvas in place while you work on it.
Step 2: Apply the Sizing
Traditionally, artists used rabbit-skin glue to size their canvases. Sizing helps prevent oil from penetrating the canvas fibers, which can cause them to weaken and deteriorate over time. However, we now have modern alternatives, such as archival acrylic and synthetic PVA (polyvinyl acetate) sizing. PVA sizing offers a reliable, flexible option that protects the canvas and makes it less prone to changes in humidity—a condition that can cause rabbit skin glue to swell or shrink.
To apply the PVA sizing, follow these steps:
1
Work directly from the container or pour a small amount of PVA sizing into a clean container.
2
Using a soft brush or sponge, apply a thin, even coat of sizing across the entire canvas. Work the brush in long, smooth strokes for full coverage.
3
Let the sizing dry completely. This may take several hours, depending on the brand you’re using and the humidity in your workspace.
Step 3: Stretch the Canvas
Once the sizing is dry, you can stretch the canvas over stretcher bars to achieve your desired tension. Stretching the canvas at this stage is key for creating a taut, stable surface that won’t sag or shift while you paint. Here’s how:
1
Lay the canvas face-down, positioning your stretcher bars on top.
2
Starting in the middle of each side, staple the canvas to the bars, pulling it tight as you work outward, toward the corners.
3
Continue stapling opposite sides, maintaining an even tension until you’ve completed all edges.
4
Fold and secure the corners neatly to finish.
Step 4: Lightly Sand the Canvas
To create a smoother surface for applying the oil ground, lightly sand the canvas with fine-grit sandpaper (like 220 grit). Sanding helps remove any small fibers that might have been raised during the sizing process and ensures the ground will adhere evenly. Brush off any dust from sanding before moving on to the next step.
Step 5: Prepare and Apply the Oil Ground
Oil ground provides a solid, absorbent layer that’s perfect for holding oil paint without sinking in or dulling. Most oil grounds are thick and may need to be thinned slightly for easier application. Use a small amount of mineral spirits to adjust the consistency, mixing thoroughly until smooth. The ground will be white, but if you prefer a toned ground, you can tint the oil ground with a small amount of oil paint, using colors like raw umber or burnt sienna to create a warm, neutral base.
When applying the oil ground:
1
Use a large putty knife or a canvas spreader to apply the ground.
2
Work in long, overlapping strokes, ensuring that the ground fills any texture in the canvas without leaving excess.
3
Apply only as much ground as needed to create a thin, even layer. Too much can result in cracking or uneven curing.
Step 6: Allow the Ground to Cure
One of the most important aspects of this process is allowing the oil ground to cure fully before beginning your painting. Oil ground cures slowly, so it’s best to let it dry for at least two to three weeks—ideally longer if possible. This curing time ensures that the surface is completely stable, preventing paint-adhesion problems or cracking later on. Store the canvas in a dust-free, well-ventilated area while it cures.
Final Thoughts
By taking the time to prepare your canvas with traditional sizing and oil ground, you’re creating a surface that will showcase the vibrancy of your oil paints while providing a strong foundation. This preparation process preserves your work for years to come, ensuring your colors remain luminous and your canvas remains intact. With practice, these steps will become a natural part of your painting routine, setting the stage for your best work yet.
