Beginner artists must learn how to prime a new canvas before even a drop of paint is applied. This process neutralizes the material’s natural tan hue so that it does not undesirably alter the overall coloring of the final painting. Priming also serves to create an even look to the final painting by making the surface smooth and non-porous. Here are simple instructions and tips for learning how to prime a canvas.
The Materials and Tools Needed For Priming a Canvas
1. Gesso – is a thick white liquid canvas primer that can be found at art supply stores. While there are other primers that are clear or color tinted, the white variety of Gesso, as described in this article, is the most common.
2. Paint Stirrer – used to thoroughly mix water or some other thinning agent with Gesso.
3. Plastic Container – this needs to be large enough to allow room to add a thinning agent if desired.
4. Gesso Application Brush – this brush has nylon bristles that can be easily washed with soap and water when finished.
5. Thinning agent and water are used to make the Gesso spread more easily and produce a smoother surface than would be possible using it straight out of the bottle.
6. Fine Sandpaper and a soft cloth – this is to be used to sand a dry, hardened layer of primer on the canvas before applying the next layer. The dampened soft cloth is used to remove the sanding dust before applying another layer of primer.
Instructions For Priming a Canvas
Tip: It is important to note that the Gesso formula commonly used today behaves in a similar way to fast drying water soluble acrylic paint. When Gesso dries it is no longer water soluble. This means that you need to keep your brush damp with water to prevent the primer from sticking to the brush as it dries. Also do not dump excess primer down the sink drain because when it dries in the trap it can produce a serious clog. Paint fast and clean your brush immediately after and you should not have much trouble.
Dilute the Gesso – For a relatively rough texture apply only one coat of undiluted Gesso right out of the bottle. For a smoother finish apply two thin coats of slightly diluted primer to the canvas.
Water is usually used to thin the primer. The ideal ratio of Gesso to water mix should be indicated on the bottle label. Too much water can cause the primer to crack on the canvas when dry. It is possible to use a 3-way mixture of water, Gesso and a special medium that prevents cracking. Ask at a local art store for recommendations.
Tip: To prevent contamination, never dilute the Gesso in its original bottle or pour unused primer back in the bottle. For the same reason do not dip the paint brush directly into the Gesso factory container. Instead pour only what you will need for one canvas into a separate plastic mixing container. Throw away what you do not use instead of returning it to the bottle.
Brush Pattern: The first coat should be painted with left to right parallel brush strokes. The second coat should be brushed from top to bottom.
Sand after the first coat: sand the canvas with very fine sandpaper after the first coat of Gesso has dried for an hour or so. This is then followed by wiping off the fine sanding dust with a slightly damp soft cloth before applying the next coat.
Drying Time: Depending on the humidity levels in the studio, let the first coat dry at least an hour or two. The second or final coat should be allowed to dry for 24 hours before beginning the painting. Always let the canvas dry while laying flat to prevent the wet Gesso from running.
Preparing a canvas to last for many years requires special priming techniques like adding a dilute formaldehyde solution to the back of the canvas to prevent bacterial decay. It is interesting to note that some of the old Masters would actually let a primed canvas stabilize for 6 months to a year before adding paint. However, these advanced techniques for learning to prime a new canvas are beyond the scope of this article.