One of the most important pieces of information that a painter requires is knowing how to prepare their canvas for painting. Some artists prefer primed canvas while others are interested in unprimed canvas. In order to better understand the differences between primed and unprimed canvas, we need some information to help us navigate this interesting and time-tested art form. Let’s discuss:
The ground or primer—an adhesive flat paint—is the initial coat applied on canvas or other materials such as wood, bare metal, new drywall, previously painted brick before painting.
A primer has about 20 to 30% synthetic resin, 60 to 80% solvent, and 2 to 5% additive agent. To achieve more longevity, some primers have polyethylene.
Priming allows sufficient adhesion of paint to the surface of the canvas in order to provide a consistent base for the coats that will be added. This increases the durability of the paint, and offers further protection to the material you are using.
It does not matter whether you are painting with oil or acrylic paint, priming provides the fabric with a smoother texture which is more impermeable. It also allows the brush to glide more smoothly over the surface, which makes it easier to work with.
Art Tip: When a canvas is primed for oil paint, which has a nonporous oil- based primer coating to make it impervious, it’s unsuitable for acrylic painting.
Unprimed canvas does not have the primer. Unprimed surfaces require more coats of painting to cover the surface sufficiently, but the paint does not always stick properly to the original surface. This creates some challenges in the long run.
The next step to learning the differences between primed and unprimed canvas is to explore the types of primers.
Since people might touch the surface, it is a good idea to use an oil-based primer, as it conceals stains very well. However, it takes longer to dry and they emit organic compounds (also known as VOCs) that may harm people who breathe in too many fumes.
Utilized for many centuries, they are great for concealing stains. Although they dry fast and are good for adhesion, they emit more fumes and require altered alcohol to thin.
Water-based primers are also known as latex primers. They are very good at resisting cracking, which is important. Although they are not as effective as shellac-based and oil-based primers, they are easier to clean and healthier to use because they have low or no organic compounds.
In the long run, since a primed canvas is likely to contain volatile organic compounds that are emitted in the atmosphere, exposure to people is potentially harmful to their health. In the absence of these emissions, unprimed canvas is safer.
Over time, a primer provides longevity to the paint because it protects the fabric from absorbing the oil in the paint, as oil wears away the canvas fiber. But there is a way to void this: seal it from contact with the oil.
Art Tip: This procedure is called ‘sizing’ because the sealant is known as ‘size’.
If canvas or paper is in contact with the oil in oil paint or oil primer, it slowly corrodes the canvas fiber. Use either rabbit skin glue (RSG) or acrylic polymer to seal it. Unprimed canvas is better especially for animal rights advocates, as they do not need to use RSG or any other product to prepare the surface.
The more absorbent the priming is, the brighter and glossier the oil colors are because the ground absorbs the oil. But the color is reduced if it is soaked into the fabric. Color in unprimed canvas is dull. However, some artists are interested in this appearance for their work. As you experiment with these methods, you will become familiar with the differences between primed and unprimed canvas. As you experiment, note the changes in how your work looks. Over time, you will find the best method for your art.
Initially, priming is more time consuming than unprimed work. In the long run, however, unprimed canvas requires more care to prevent the surface from cracking, as it requires more coats to conceal stains.
Art Tip: After the primer is dry, it is important not to wait too long to apply the other coats of paint. Read the manufacturer’s instructions to find out how fast you ought to start painting when the primer has dried properly.
Since you know the difference between the two processes, now would be a great time to apply that knowledge in your next steps toward achieving your artistic goals.
Should you have further questions, please do not hesitate to contact us today.