More on grounds
What is the best primer?
What primer would best suit my art project?
- Acrylic Gesso
- has a slight tooth which can be sanded down to make a super smooth surface if required. It is more absorbent than regular acrylic primer and is well suited to watercolour types effects in acrylic and oil. Stains are easily created on an acrylic gessoed surface. We recommend 3 layers of acrylic gesso for a surface that can be painted on with oils as well as acrylic.
- Acrylic Primer
- a less absorbent white ground than acrylic gesso, which can be applied to a number of natural surfaces such as wood and canvas. Versatile, opaque and worth keeping in your studio supplies!
- Oil Primer
- Oil based primer which dries to a more slippery finish. Can be thinned with solvents if necessary and tinted with quantities of oil colour. Use only if you intend to paint with oils - it is not advised to paint acrylic paint on to an oil primed surface as it takes longer to dry and will undermine the structure of your paint surface.
Clear acrylic medium can be used as a clear acrylic size on all surfaces that you wish to paint oil and acrylic paint on to. Follow the instructions of your chosen product to find out the recommended number of coats, although as a general rule 3 coats of acrylic primer medium will be sufficient for both acrylic and oil painting. we also sell special grounds that are specially developed for use by pastel painters and watercolour painters. In this category you will also find the ingredients to make your own traditional gesso: Rabbit skin glue and Whiting (French Chalk).
Oil Based Primers
Nowadays, all oil based primer for oil painting tend to be made from Titanium pigment, china clay, and a binder made of linseed oil and alkyd resin. Oil primer is slippery and allows the paint to glide around the surface. It is less absorbent and tends to be a warmed tint of white than most acrylic primers. Oil primers can be tinted with oil colour prior to application.
Oil primers are only suitable for oil painting and not compatible with acrylic or watercolour painting. Oil primer should not be applied to raw natural fibres as they will cause them to rot over time. Surfaces must be sized first to prevent rotting, with rabbit skin glue or an acrylic alternative.
Gesso and Acrylic Primers
There are 2 main types of acrylic primer – regular acrylic primer and gesso. Both are made up of acrylic resins mixed with pigment, they are cheaper than artist acrylic colour because they contain opacifiers to ensure that they provide good coverage. Acrylic Gesso replicates the qualities of traditional gesso, a mixture of French chalk or whiting and rabbit skin glue, and is absorbent with a slightly heavier tooth than acrylic primer – the more layers you apply the more absorbent. Because of this a few coats is required if you are going to apply oil colour to it, as there is a rick of the oil sinking down to the fibres of the canvas support and causing damage. You can also choose to prime your canvas with a black gesso primer by System 3 or Golden Paints if you prefer to work on black (this will have a dramatically different effect on your transparent colours). Acrylic clear primer allows you to work on the natural colour of the canvas without having the absorbency of the raw fabric.
Primer dries smoother and is not absorbent, but a few coats with light sanding in between will make a good solid surface on which to paint. The white colour of regular gesso or primer helps colours to maintain their luminosity. All white gessos and primers can be tinted by adding acrylic colour and mixing. Acrylic primer, unlike oil primer, does not cause natural fibres to rot over time so can be used without the use of glue size. Many oil painters today use acrylic primer instead of rabbit skin glue size as it does not require heating, and its white hue means you need fewer coats of white lead oil primer to achieve a bright white, glossy surface.
Gessos and Primers should be applied to surfaces as thinly and evenly as possible - more thin layers creates a superior surface on which to work than fewer thick coats. We recommend the use of a wide, relatively springy soft hog hair flat brush. Sanding the primer/gesso surface between coats with fine sand or glass paper will create a super-smooth surface.
How to Prime (Advice applies to both acrylic and oil primer)
Use a synthetic or relatively soft hog hair brush that is clean and dry. Load with primer and apply evenly by brushing the paint on in random, varied directions. If the paint is not gliding on easily dilute it (with water if it is acrylic or solvent if it is oil). Keep the layer of primer as thin as possible and leave to dry – at least 3-4 hours for acrylic primer and overnight for oil primer. Then apply a new layer if necessary. The more layers of primer the less absorbent the canvas will feel, and the brighter your colours will appear. Most artists tend to apply 2-3 layers before considering a canvas ready for working on. If you like a particularly smooth surface on which to work, gently rub a fine piece of glass or sandpaper over the canvas to remove any lumps that may have appeared in the primer.
Pastel ground is an acrylic based primer that is quick drying and posesses a fine tooth that is suitable for pastel painting. It can be applied to most clean dry surfacese; all types of papers (300gsm or heavier is recommended), canvas, card, ply, plastic, glass, timber, ceramic or metal. Pastel ground can be applied with brushes, sponges, rollers, or straight from the pot. They can be tinted with fluid acrylic. Pastel ground can also be used for oil or acrylic painting, where a rough surface is desired.
Watercolour ground is a smooth, acrylic based primer that is available clear or pigmented that can be applied to natural surfaces to make them sufficiently absorbent to take watercolour. 3 layers (that have been allowed to sufficiently dry between each layer) will optimise the absorbency and allow you to achieve the same watercolour effects possible on regular watercolour paper. Apply with a soft clean brush.
Oil painters must coat or ‘size’ their canvas prior to painting in order to prevent the oils of the paint seeping into the fibres and causing them to rot. Traditionally artists use a layer of rabbit skin glue to size their canvases. Rabbit skin glue usually comes in bags of dried granules, which are best melted in a bain marie (double boiler). The idea is to use a relatively soft haired brush to apply this very fluid, warm (and smelly!) substance to the canvas, working it into the grain and allowing the glue to laminate the threads. It should not be applied so thickly that a layer of the glue is noticeable. Rabbit skin glue is also available as a jelly like substance which thins out on heating. As well as forming a barrier between the oil and natural fibre of the canvas the glue will also cause the canvas to shrink slightly, thus tightening the canvas to the frame and increasing the tension or ‘spring’. Research has proven that rabbit skin glue is slightly hygroscopic - this means it absorbs water in humid conditions and when it does this it will swell. Repeated swelling and contracting caused by the natural changes of humidity in the air will, over time, cause a finished painting to crack. A number of non-hygroscopic acrylic mediums (AV, Jackson’s, Golden) have been developed and many artists prefer to size their canvases with these alternatives because they believe their work will not deteriorate over time – however because these are recent developments, acrylic mediums have not had the test of time to prove that they are wholly suited to the purpose of sizing canvas.
Silver Point Grounds
Silverpoint / Drawing Ground is a liquid acrylic used for the preparation of supports for drawing media. The ground is designed for the achievement of fine detailed lines on a permanent, lightfast, flexible ground. Silverpoint / Drawing Ground is ideal for use with metal styli or other drawing tools. It is formulated with 100% acrylic polymer emulsion, a low viscosity fluid that contains high levels of titanium dioxide and prepares surfaces to readily accept marks from a metal stylus.
Golden Silverpoint / Drawing Ground is designed for thin applications only. When applied too thickly the film may crack upon curing. A single thin coat is typically sufficient. It can be brush or spray applied to paper, primed canvas, wood or any surface that will accept a water-based coating. The most common substrate for metal point drawing is heavy weight hot pressed watercolour paper. Note: Because lower weight papers are susceptible to buckling from the moisture in the Silverpoint / Drawing Ground, some artists may find taping the edges down will help prevent extensive warping.