Table of contents
- Spotlight on Gesso Primer
- How to gesso a raw canvas for acrylic painting
- Frequently Asked Questions
Spotlight on Gesso Primer
Spotlight on Gesso Primer – makes your paintings brighter and your paint go further. Acrylic primer is suitable for acrylic and oil painting.
Gesso, pronounced ‘jesso‘, was traditionally used to prepare or prime a surface so Oil paint would adhere to it. Gesso is the same as a primer, as in ‘pre-primed canvas’.
It is made from a combination of paint pigment, chalk and binder. It is recommended that you apply further layers of Gesso to pre primed canvas as often this is a single layer and still leaves canvas semi raw, so still absorbent.
Traditional Oil ‘glue gesso’ was made with an animal glue binder, usually rabbit-skin glue, chalk, and white pigment, usually Titanium white.
Gesso is usually white or off-white and is used after you have sealed the raw canvas with a coat of size.
It creates a surface that is both absorbent (particularly useful for ‘dead’ colouring with oils) and has a ‘tooth’ (texture) that allows paint to grab onto the surface.
So what is Acrylic Gesso?
Modern acrylic gesso is a combination of calcium carbonate (chalk) with an acrylic polymer medium (binder), a pigment (titanium white) and other chemicals that ensure flexibility, and ensure long archival life.
Why do I need to use a gesso primer for Acrylic painting?
Technically you don’t.
But in practice painting directly onto a raw canvas is not an enjoyable experience. Unless you are interested in deep staining effects like Morris Louis who became fascinated with using diluted acrylic paint to stain the raw canvas, rather than apply with a brush.
Can I use acrylic gesso under an oil painting?
Yes and no.
Yes for 90% of your paintings especially if your just beginning ‘acrylic gesso‘ will be fine if the raw canvas has been properly sized, thus protecting the canvas from the corrosive nature of oil.
However, if it was for a portrait or to produce a masterpiece for your painting legacy I would use an Oil based Primer purely for the fact it has been time-tested and the Oil will always adhere better to Oil than sitting on top of an Acrylic. We don’t stock oil primer but can order this in for you.
Tip: If you want the first layer of paint to dry quicker than it normally might, just add gesso. The gesso primer layer can soak up the oil from within the paint and leave a ‘dead’ flat underpainting that won’t have any sheen to it. Imagine the difference between painting onto glass and painting onto blotting paper. All the oil from the paint would be absorbed into the primer layer.
Homemade or ready-made?
Shop bought gesso comes pre-prepared in tubs or tubes and is pretty good, homemade gesso is cheaper to produce and can be adjusted to personal needs and tastes, however, it’s not needed when you are first starting painting.
Artist or Student quality?
As with paints, the difference between the two is dependent on price. The artist quality having a higher price, more pigment, and a higher opacity. The student quality will have a lower quantity of pigment and more filler. If you are painting onto a raw canvas the artist quality would be best due to the increased opacity. For adding a bit more absorbency to a pre-primed canvas student quality would be fine (you can always add extra white pigment to it).
You can browse our range of Gesso Primer here
You can find Student Quality Gesso here
Can I colour the gesso?
Yes. If you are pushed for time you can mix some paint into the gesso to tint it. You can also buy premixed black gesso and clear gesso. For example, if you are painting a blue seascape the warm undertone of Yellow Ochre can balance perfectly to the cool blues in the scene, adding the feeling of the sun hitting parts of your painting.
Pre-primed canvas boards
“Pre-primed” means “pre-gesso” It already has a gesso layer applied in the factory. On cheaper ranges for some manufacturers often use a seal on top which creates a shiny surface which defeats the object of gesso.
If you are using watered down paint or student quality paints this shiny surface can repel the paint.
The more watery the paint the easier it will sit on the surface and not soak into the canvas as you would like. Winsor & Newton don’t do this, their boards are ready to paint on as ‘pre primed’ – although as previously discussed we would recommend an additional coat of Gesso primer.
If you apply a couple of coats of gesso it will form a more absorbent surface due to the chalk (calcium carbonate- known as ‘whiting’ in oil painting) found in the gesso.
Creating a super smooth finish
You can sand gesso between coats to create a lovely smooth finish, especially handy for photo-realistic paintings, just sand each layer with a fine sandpaper. Say a 240 grit. 3M’s make a good sandpaper. Just make sure you do it outside, or in a well-ventilated area as it goes everywhere!
How to gesso a raw canvas for acrylic painting
What You Need:
- Tub of Gesso primer
- Large flat brush
- Kitchen Roll
- 240 grit sandpaper if you want to sand the layers in between each other.
Buy a tub of premixed white gesso and give it a stir. You can work directly from the tub so you can control the amount of gesso on your brush for each stroke, but you can also buy it in tubes.
The first coat always needs to be diluted with a touch of water (sometimes people recommend adding a bit of acrylic medium to prevent cracking, but the layer is so thin and soaks straight in, it would never crack).
Allow to dry, then apply a second coat. This can be applied thinly and does not be watered down. If you want a more absorbent surface, add another layer.
When applying the gesso turn the canvas 90 degrees between coats to ensure an even coverage.
Apply a final coat using the pure, undiluted gesso.
Using a large flat brush, apply the gesso directly to the stretched canvas in even strokes. Work from the top to the bottom of the canvas, in parallel strokes from one edge to the other.
Wash your brush out immediately in running water then use a brush cleaner to thoroughly remove the gesso out. It’s worth cleaning it twice even if you think it’s clean.
Frequently Asked Questions
A common question regarding acrylic painting is if you need to use a gesso primer. Technically, you don’t. It provides you with a nice, slightly more absorbent surface to work on, especially if your working on board or raw canvas, but for a pre-primed canvas it’s unnecessary
What are the alternatives to gesso? You can prime a canvas with acrylic mediums, clear gesso, or rabbit skin glue. If you work with acrylics, you can also paint directly on raw canvas without priming it first. Oil paints require a primer to protect the canvas from the linseed oil found in oil paints.
It dries hard, making the surface more stiff. Gesso prepares (or “primes”) the surface for painting, making the surface slightly textured and ready to accept acrylic paint. Without gesso, the paint would soak into the weave of the canvas.
When you add gesso to your acrylic paint, you’ll achieve a matte or, depending on the ratio of acrylic paint to gesso, a satin finish. Often the first layers of my paintings, although painted with acrylic, are applied in a very fluid and thin manner, much like watercolor.
Liquid white is not the same thing as gesso! Gesso has an acrylic base, so you don’t want to mix your oil paints into that. Gesso needs to be completely dry before adding any sort of oil paint or medium on top.
If you want to apply an additional coat of gesso, you only have to wait until it’s dry to the touch. Allow it to dry for at least 24 hours before painting on it with oils. If you’re using acrylics, then you can start painting as soon as it’s dry to the touch.
The most popular surfaces for painting with acrylics are canvas, wood, or paper. But once primed with gesso, acrylics can be painted on almost any surface, such as fabric, clay, or even your old vinyl records! … When properly varnished, acrylic paintings do not need to be framed behind glass.