Priming a canvas for acrylic painting is an important fist step. A properly primed canvas ensures that the acrylic paint will properly adhere to the substrate. Depending on the type of primer used, it can also improve the vibrancy of your colours. In this article I will examine some of the benefits to priming a canvas and Some of the common materials used for canvas priming. I will also explain the steps to take to properly prime an acrylic canvas.
PRIMING, AN IMPORTANT ACRYLIC PAINTING TECHNIQUE
Many canvases come pre-stretched and pre-primed. Others come primed and just need to be stretched over a canvas stretcher. If you are using either of these options from a trusted canvas manufacturer, then you can probably just paint on them without any additional steps. On the other hand if you are using raw canvas, you will have the best results if you add a primer layer. Some artists also find that the pre-primed variety of canvas isn’t quite enough of a base layer. They find that this primer isn’t quite enough and can’t tend to “suck up” a lot of the paint they apply. They also find that by adding an additional layer of primer, the paint can be applied in a smoother way, with less of a “dry brush” effect. Either way it is up to personal preference.
DIFFERENCES BETWEEN PRIMING A CANVAS FOR OIL PAINT AND PRIMING A CANVAS FOR ACRYLIC PAINT
As an acrylic painter, you have it much easier in many ways then your oil painting counterparts. You can easily clean your brushes with water. The paint dries quickly so, if you make a mistake, you can just wait a couple of minutes and then paint over it. You don’t have to wait months and months before you can varnish your painting. But, one of the biggest benefits to acrylic paint, is that it is relatively forgiving when it comes to priming. Oil paintings can run into many problems if the canvas isn’t properly primed. If a sizing layer isn’t applied, the paint can soak into the cotton canvas fibres and eventually rot it. If a size like rabbit skin glue is used, problems like cracking can happen down the road, as the rabbit skin glue, will absorb moisture from the atmosphere and shrink and contract at different rates then the oil paint itself. That is why properly priming an oil painting is so important, and a topic that we cover in this article.
Acrylic paint on the other hand is much more flexible. Some artists even paint directly on the raw canvas. This technique was pioneered by artists like Morris Louis. Using the early versions of acrylic paint, he would thin them down and “stain” them onto the canvas. This was almost similar to the way watercolour paints “stain” watercolour paper. The technique was adopted by other artists as well.
The downside to working this way and painting directly onto raw canvas, is the risk of support induced discolouration or SID.
WHAT IS SUPPORT INDUCED DISCOLOURATION (SID)?
Support induced discolouration is when impurities from the surface you are painting on leach into the acrylic paint and cause it to yellow or change colours. If you are working on Canvas, the most likely source of SID would probably be the wood from the stretcher bars. The good news is that priming the canvas with the right materials can greatly reduce the chances of SID occurring. The following video discusses SID and what you can do to prevent it.
WHAT MATERIALS WILL I NEED?
The main ingredient used for priming canvases is a ground like an acrylic gesso. Gesso was originally developed when oil painters were working primarily on wood panel. They combined rabbit skin glue, and chalk or another white substance. This was applied as a first layer to the wood to effectively seal it from the oil paint. Many layers would be applied, and they were often sanded during each coat. This created a very smooth surface to paint on. It allowed light to pass through the layers of oil glazes and reflect back through the surface of the painting. Unfortunately traditional gesso doesn’t work very well on canvas. It is very brittle when dry, and if it isn’t applied to a rigid support like a wood panel it can crack–cracking the oil paint along with it.
Today’s gesso is made primarily from the same acrylic polymers as acrylic paint is. So it is much more flexible. The difference between gesso and regular paint, is that gesso tends to have a higher ratio of pigment to binder (the binder in this case being acrylic polymer). A high quality acrylic Gesso like the one made by Golden has enough acrylic polymer in it that it remains some flexibility after its dried. This helps to prevent it from cracking. The main colour it comes in is white, but black gesso is also available. There are also high load acrylics which come in various colours and can serve a similar purpose. The difference between using a gesso or high load acrylic and normal acrylic paint is that the gesso and high load acrylic dry matte. The matteness and high pigment load improve the binding of subsequent layers of paint.
A sizing liquid like Golden AC 100 may also be used in combination with the gesso. This will help to reduce the occurance of SID. See the manufacturers instructions on how to use these two products together for best results.
HOW TO PRIME A CANVAS FOR ACRYLIC PAINTING
The following steps will outline how to prime a raw canvas for painting. If you are are using a pre-primed canvas and would like extra insurance from SID, you can follow the same steps and just paint the primer over the existing primed canvas.
STEP 1: STRETCH THE CANVAS
Raw canvas needs to be stretched over a canvas stretcher. It can also be stretched over a panel (wood, dibond, aluminum), or laminated to one of these types of panels.
STEP 2: APPLY THE PRIMER
Following the manufacturers directions, apply the acrylic gesso. You can use a brush or a squeegee. Two thin coats will help ensure even coverage. If you apply it too thick, there is chance you could have visible brush marks.
STEP 3: LET IT DRY
That is it! Let it dry and you can start painting. Priming is one of those acrylic painting techniques that can be very useful, especially if you are stretching your own raw canvas.