Whether stretched, mounted to a board or a panel, or used in a pad, canvas is one of the most popular painting supports for artists. It is available unprimed, oil primed or universally primed, and in a choice of different weights and textures, from rough jute to fine linen. Its versatility makes canvas suitable for a range of different painting mediums and techniques, but it is not traditionally associated with watercolour painting.
Universally primed canvas is prepared for oil and acrylic paint, but is not absorbent enough for watercolour. An effective watercolour surface, such as watercolour paper, needs to be absorbent enough to stabilise the paint, but not so porous that the paint sinks into the surface and becomes dull. Watercolour grounds are acrylic-based primers designed to provide the perfect amount of absorbency, and they can be used to adapt any universally primed canvas for watercolour painting.
Painting with watercolour on canvas, instead of paper, can offer several advantages:
Canvas is a very durable support.
As a thin, soft material, even the highest quality watercolour papers are very easily damaged in storage or in transit if they aren’t properly protected. A stretched canvas or canvas board makes for a more rigid and durable art object which is less vulnerable to wear and tear. A painting on stretched canvas is also easier to conserve – if the stretcher bars are damaged or become warped over time, the painting can be removed and stretched across a new frame.
An opportunity to work on a large scale.
In most watercolour paper ranges, the largest sheet size available is full imperial (approximately 76cm x 56cm). To work on a larger scale, often the only option is to buy the paper on a roll. Stretched canvases are available in a number of different sizes, the largest ready-made size available from Jackson’s is 120cm x 150cm, but you can work even larger if you build your own stretcher and stretch the canvas yourself.
There are options to hang the work without mounting or framing.
To hang a painting made on watercolour paper without damaging the artwork, the paper should be mounted to a rigid support, such as a wooden panel, or framed. A stretched canvas can be hung without framing or mounting, as hanging hardware can be screwed straight into the wooden stretchers. Uncradled supports, like canvas boards, can be hung by glueing strips of wood to the back of the piece and attaching hanging hardware to the wood.
With pre-stretched canvases, there is no need to stretch the surface.
To avoid buckling, watercolour paper should be stretched before painting, especially if using a lot of water. If using a stretched canvas or a canvas board, there is no stretching needed. After applying the watercolour ground, you can get straight to painting.
Comparing seven watercolour grounds on canvas
The comparisons were made on Jackson’s Premium Cotton Canvas Art Boards. They have a medium grain and are universally primed with white acrylic primer, so no further preparation was needed before applying the watercolour ground. Each watercolour ground was applied according to the recommendations given by the manufacturer. All grounds were applied in two thin layers, with the exception of Schmincke’s Aqua Primer Fine, for which it is recommended to use three layers.
Once the watercolour grounds were dry for at least 24 hours, the following tests were made:
A granulating wash of equal parts Jackson’s Cerulean Blue Artist Watercolour (PB35) and Daniel Smith Cobalt Violet Watercolour (PV49)
This test assesses how responsive the texture is to granulating paints. Granulation is a property specific to certain pigments with heavy or irregularly sized pigment particles. The particles separate and settle in the valleys of the surface, creating a textural effect.
A lifting test with Jackson’s Permanent Sap Green Artist Watercolour
Permanent Sap Green is a mixture of Ultramarine Blue (PB29) and Benzimidazolone Yellow (PY154) and it is a moderately staining colour. Lifting is a common technique used to correct mistakes or create highlights, but it is not essential for all watercolourists. Each Permanent Sap Green swatch was allowed to dry completely and then a wet, firm brush was used to re-work a section of the paint. The wet paint was blotted with a cloth to lift away the colour. Highly absorbent surfaces are usually harder to lift from.
A soft pastel mark, using Jackson’s Handmade Soft Pastel Cool Grey VI
This is to assess tooth, or the ‘grip’ that a surface has. An abrasive surface allows good adhesion of dry media like soft pastels and charcoal, an opportunity for mixed media artists.
This test is used on watercolour paper to assess how absorbent it is. The pigment, PR122, is prone to blossoming when used diluted. When the paint is not absorbed quickly, or is absorbed unevenly, a bead of paint might gather and then blossom outwards, creating an effect known as a backrun (or sometimes, more descriptively, as a ‘cauliflower’). Watercolour usually takes longer to dry on hot pressed watercolour paper than on rough watercolour paper, and therefore backruns are more likely on hot-pressed watercolour paper. It will be interesting to see if the same rules apply to watercolour grounds.
The ground produced a smooth surface that retained the texture of the canvas underneath. As a result, the granulating wash created a very interesting effect as the pigment settled along the canvas grain.
As the paint was drying, I noticed that it dried unevenly – in some parts the paint was absorbed into the ground quickly, while in others it remained wet for a long time. A backrun formed in the Quinacridone Purple where the paint was sitting on the surface without being absorbed. The effect can also be seen in the granulating wash where there are patches of darker colour lower down in the wash where the water had pooled and the pigment had gathered there.
The Permanent Sap Green lifted cleanly. Even though the ground underneath was stained yellow, it made a good highlight.
Aqua Primer Fine is abrasive, and it gave the canvas a wonderful tooth, producing a clean and dark pastel mark. This makes it ideal for artists who introduce dry mediums, such as pencil, charcoal or pastel, into their watercolour paintings.
The palette knife application of this ground completely hid the canvas grain, creating a surface that was comparable to rough watercolour paper. The texture complemented the granulating wash, as the heavy pigment particles settled in the pits of the surface. You can see in the Permanent Sap Green swatch that the paint was caught within the surface texture, making it difficult to lift away the colour entirely. The ground is toothy and very rough, giving a broken soft pastel line.
This coarse ground can be applied flat, like above, to imitate the textural quality of rough watercolour paper, but it can also be applied impasto to create a structured surface to paint on. The sample below was made on a smaller canvas board, using the end of the palette knife to make impasto effects:
The primer dried to a satin, transparent finish which did not affect the texture or colour of the surface underneath. It seemed to be the least absorbent of all of the tested watercolour grounds – the dilute washes took a long time to dry, which would be useful for allowing longer periods of blending. The Permanent Sap Green could essentially be wiped completely away once re-wetted.
The Quinacridone Purple didn’t produce a backrun, which I was expecting on such a non-absorbent surface. Instead, the paint gathered in the corner of the swatch and the water eventually evaporated, leaving a shiny area of dried gum arabic binder on the surface. Glazing, a technique of building up transparent layers, would be hard to do effectively on this ground because the paint would be easily moved when new layers are applied. This characteristic means that the paint can be reworked and blended even after drying.
An interesting possibility with this ground is that it can be used on top of dry acrylic paintings, to allow overpainting with watercolours. It can also be used over clear-sized canvas, to keep the original colour of the canvas, as below:
Looking at Golden’s Absorbent Ground in comparison with Schmincke’s Aqua Transparent Primer, the effect that absorbency has on colour vibrancy is clear. The highly porous nature of the Absorbent Ground gives the colours a muted effect, while the same colours on the less absorbent Transparent Primer are more vibrant.
While Schmincke’s Aqua Primer Transparent leaves the paint easily moved, Golden Absorbent ground makes a more stable watercolour surface which would be better suited to glazing. The paint was quickly drawn into the ground, and became very resistant to lifting once dry.
Golden Absorbent Ground has a gesso-like feel and gave a toothy finish. It makes a good ground for incorporating dry media into watercolour painting.
Like Golden’s Absorbent Ground, Golden Qor Cold Pressed Ground absorbed the paint quickly. The difference is that the Qor ground contains a fibrous material (which looks and feels like paper pulp) to give it a watercolour paper-like texture. Note where the primer has been brushed over the edge of the canvas board, creating a deckled edge effect. I applied the ground with a brush, and you can see that there are horizontal brush marks remaining. The ground can also, like Schmincke’s coarse primer, be applied with a palette knife.
Lifting, which was difficult due to the highly absorbent surface, was made harder by the texture. Ultramarine blue, the heaviest pigment in Permanent Sap Green, was caught in the grooves of the surface.
Unlike watercolour paper, the texture feels ‘sharp’ and highly abrasive. The soft pastel crumbled as I drew it over the ground.
All of the above watercolour grounds can be tinted with watercolour or acrylic paint, but Daniel Smith produces a range of coloured grounds for watercolour. Their Iridescent Gold ground is highly pigmented and opaque with the richness of real gold. A gold background completely changes the qualities of the colours, giving them a warm and luminous undertone.
The colours remained vibrant, and this can be attributed to the fact that the ground is relatively non-absorbent, so the pigment sits on the surface. This was indicated by the fact that the Permanent Sap Green swatch was very easily lifted and removed almost entirely from the ground.
I hesitated before applying the same colours to the black ground, because I wasn’t sure if it was only suited to opaque or metallic paints. However, I was proven wrong as the colours glowed against the black background. The only exception was Quinacridone Purple which, being dilute and transparent, was slightly lost. While Daniel Smith’s Iridescent Gold ground gave the colours warmth, the black ground makes them appear cooler.
Like Daniel Smith’s Iridescent Gold watercolour ground, the surface was abrasive and excellent for soft pastel. The white soft pastel would be ideal for creating strong highlights.
Protecting artworks on watercolour ground.
A finished work can be sprayed with a fixative, such as Schmincke’s Watercolour Fixative, which creates a thin, water-resistant barrier to protect from dust and humidity. For the samples I made for this post, a general fixative like Lascaux Fixative would be more effective at fixing both the watercolour and the soft pastel.
Watercolour paintings on paper are not commonly varnished, because the addition of an acrylic coating can alter the colour, texture and sheen of the watercolour. However, Golden recommend their Archival Varnish Aerosol, applied in several thin coats, for use as a varnish for watercolour on a watercolour ground. Once the watercolour is fixed with the spray varnish, a brush-on varnish could be applied but, like when varnishing any artwork, it’s best to test the application first before using it on a finished piece.
Brush-on varnishes are not suitable unless the watercolour is adequately fixed as it would reactivate the paint, causing it to streak.
The variation between the grounds allows for a range of different watercolour techniques and approaches. A non-absorbent ground, like Schmincke’s Transparent Primer, allows the paint to be easily lifted and reworked after drying. On the other hand, a more porous ground like Golden Absorbent Ground binds the watercolour more securely to the surface, making it better for glazing techniques. The canvas grain can be obscured entirely by applying Schmincke Coarse Primer or Golden Qor Cold Pressed Ground with a palette knife, or the canvas texture can become part of the painting by using Schmincke Fine Primer and allowing granulating washes to settle in the canvas weave.
Using a watercolour ground is not just a case of adapting a surface to accept watercolour. It is also a creative decision in itself, controlling absorbency and texture to determine how watercolour behaves.
Canvas supports from Jacksons:
A watercolour ground can be applied to any universally primed canvas surface, but would not be suitable for oil primed canvas.
- Universally Primed Premium Stretched Cotton Canvases
- Universally Primed Cotton Canvas Art Boards
- Jackson’s Handmade Linen Boards
- Bespoke canvas builder
More articles about watercolour painting surfaces:
- Black Watercolour Painting Comparison
- A Review of Yupo Paper
- Understanding Watercolour Paper Textures
The tests on watercolour grounds were inspired by Bruce MacEvoy’s method for testing watercolour paper.