Jo Sonja's Gesso
"Grounds" are products used to prepare a surface for acrylic and/or oil painting. Good preparation will not only ensure good paint adhesion, but will prove more economical as less paint will be absorbed into the surface. Although acrylics can be applied directly to a surface without first applying a ground, the acrylic binder from the paint is absorbed too quickly into the surface being worked on. The result is a drab and disappointing painting, with a disagreeably fast drying speed. Acrylic grounds are recommended before painting.
Jo Sonja's Gesso is a flexible acrylic ground with a high grit content which provides "tooth" on which to paint. It is not water absorbent and does not suck the moisture out of your paint when you start to work on it.
Available in black and white, Jo Sonja's Gesso may be used instead of, or as well as, All Purpose Sealer. Usually
applied on very porous or uneven surfaces, the grit will have a slight levelling effect, which is beneficial for inferior surfaces or rough edges. Note: For deep grain or blemishes we recommend Jo Sonja's Wood Filler for levelling.
- Apply to clean, dry surface; allow to dry before proceeding with more coats.
- A hair dryer may be used. Apply as many coats as required.
- May be sanded between coats if desired. Sanding is recommended prior to over painting over to provide a smooth surface. Use dry sanding method, not wet.
White Gesso may be tinted with regular Jo Sonja's Artists' Colours to create a 'pastel primer'.
Black Gesso makes an excellent blackboard paint. A light sanding is recommended to smooth the surface for chalk.
Gesso is excellent to apply prior to base coating with a transparent colour, ie Raw Sienna. The white or black colour will add 'opacity' to the subsequent coats of paint. The result will be a brighter, more solid base coat.
White Gesso may be thinned with water or Clear Glaze Medium and applied as a wood wash or liming glaze. The more Gesso in the mix, the 'chalkier' the effect.
Brown stain penetrating through White Gessoed surface
Apply 2 - 3 coats of Tannin Sealer two weeks prior to applying Gesso. Old furniture can often 'stain' through an acrylic base coat -particularly light colours.
Gesso thickening in jar:
Thin with water at time of application, or use Flow Medium. Do not add medium or water directly to the jar.
Surface difficult to sand:
Use a stronger grade of paper; automotive emery papers are often excellent for this application.