By Winsor and Newton
Priming for Oil Colour
Priming your canvas by applying a layer or two of gesso to the surface will help the colours in your work really stand out. When using oil colour on canvas, and the canvas is poorly primed, the oil may sink into the canvas and leave dull patches on the surface of your painting. Priming also gives the canvas a smoother surface to work on and allows your brush to flow much better.
Priming for Acrylic Colour
Priming a canvas is also recommended when using acrylic colour as it will give a solid foundation for your work.
5 points to consider when priming:
1. Tooth: Tooth is how the surface feels, the more tooth a surface has the rougher it feels to touch. The primed surface needs to provide a necessary grip for the colour.
2. Absorbency: Priming limits the absorbency of the canvas and helps with the adhesion of the paint film to the primed surface.
3. Colour: The relationship of the colour of your primed surface to the colours you use in your work is important to consider. Oils become increasingly transparent as time goes by and an opaque white primed surface will reflect back the maximum light. Take a look at JMW Turner’s sunsets to see how a painting can become brighter over time.
4. Rigidity: Primers add rigidity. This compliments the nature of the paint film and ensures long term stability.
5. Coverage: It needs to be adequate for the purpose. Generally, one or two coats of a good quality primer should be sufficient.
Oil or Acrylic Primers
Winsor & Newton offer both Acrylic and Oil Primers, both of which can be used underneath oil painting. Oil painting primer (or solvent-based primer) is the more traditional option and today it is faster drying than the very old style primers for oil colour.
It is recommended that canvases be sized with rabbit skin glue before applying a primer and once applied, you can apply a primer when it is touch dry. ‘Sizing’ is the process that fills the pores in the surface with glutinous material (rabbit skin glue or PVA) and helps to stop fluid leaking through, and it also helps stiffen the fabric. For best results it is recommended to apply a few coats.
The characteristics of acrylic primers means that they have become the preferred option for oil painting and are being chosen over oil and alkyd based canvas primers. The pigmentation of acrylic primers is carefully controlled and gives sufficient flexibility to avoid cracking, but sufficient rigidity to maintain the tension of the canvas and the correct degree of tooth and absorbency to ensure good adhesion when overpainted with either oil or acrylic.
Priming with PVA
While some artists may choose this method, using poly vinyl acetate (PVA) as a primer is not recommended because it may disintegrate prematurely, leaving the remaining painting with no foundations.
You do not have to size and prime a canvas yourself as Winsor & Newton offers a range of acrylic primed cotton and linen pre-stretched canvases in both regular and depth stretcher bars. See the range here.
Winsor & Newton Artist’s Canvas Boards are great for students and painting outside the studio thanks to their portability. They come ready sized and primed in various sizes and can be used with oil, water mixable oil, alkyd and acrylic colours.