Gesso and Watercolour Ground Recipes

This project will teach you three different things:

1) How to make your own gesso

2) How to turn regular gesso into watercolour ground

3) How to make a plywood panel for painting that you can hang directly onto the wall

Gesso is used to prime canvases and boards for acrylic and oil painting, but it's not suitable for watercolour painting as it isn't absorbent enough, and this recipe will show you how to tweak a gesso recipe to make it receptive to watercolour paint. I'll run through how to make gesso from scratch, but you can use shop bought gesso to make the watercolour ground if you want to.

For the gesso:
1/3 cup PVA glue (use the pH neutral / acid free type)
Equal parts French Chalk (calcium carbonate / whiting)
Dust mask for use when handling and mixing the French Chalk
Titanium white acrylic paint (if you want your gesso to be tinted, you can add any colour of acrylic paint you like)
Water
Mixing bowl
Spoon
Recycled jar
Pantyhose / nylon stocking
Scissors

For the watercolour ground:
175-200ml gesso
3-4tsp bicarbonate soda (bread soda)

For the plywood panel:
19mm (3/4") plywood
Drill with spade bit
Sandpaper
Crystal clear type spray varnish
Gesso or watercolour ground, depending on what type of paint you're using
Wide, flat brush for applying the ground

To make your gesso, take a mixing bowl and pour in about 175ml of your PVA glue. Add equal parts of your French Chalk (also known as calcium carbonate or whiting) and a squeeze of your titanium white acrylic paint. Wear a dust mask when handling the French Chalk.

Mix these three ingredients together into a thick paste with your spoon. Add more titanium white paint if your mixture is looking too grey. When you're happy with your mix of ingredients, add a little water at a time until your mixture has a paint-like consistency.

Cut a foot section off a pair of nylon pantyhose and place it over the opening of your jar. Pour in your gesso mixture and squeeze it through the pantyhose to strain out any large particles. This can get a little messy, so put down some scrap paper on your table and have a rag nearby to wipe your hands clean.

Your gesso is now ready to use!

Watercolour paper is the perfect medium for painting with watercolour and gouache paints, but sometimes you need to paint on different shapes and surfaces, and this is where watercolour ground comes in. Watercolour ground is applied to a surface the same way as gesso is, but it includes an absorbent ingredient that makes it receptive to watercolour and gouache paints.

To turn your regular gesso into watercolour ground, simply mix 3 to 4 teaspoons of bicarbonate soda (also known as bread soda, and available from the baking section of most supermarkets) into your gesso. That's it!

Keep in mind that bicarb soda is not just used for absorption; it's also a common abrasive, so be careful to clean your paint brushes well when painting on surfaces primed with this watercolour ground recipe. If in doubt, use older or less expensive brushes.

Take a piece of 9mm (3/4") thick plywood and, using a spade bit, drill a hole part way through the panel in the centre horizontally, and just below the top edge.

Sand the front, back and edges of your plywood panel with a fine grade of sandpaper.

Seal the front back and sides of your plywood with a clear coat of varnish. I used a spray varnish called Crystal Clear. When the first coat of varnish is dry, add a second coat and allow it to dry fully. The varnish will protect the unfinished surfaces of the wood, and the varnish that's underneath your gesso/ground will protect the paint from any acid leaching through from your wood over time.

When your varnish is dry, it's time to prime the front surface with your gesso or watercolour ground. If you're going to be painting with acrylic paint, prime with at least two layers of gesso. If you will be oil painting, prime with at least four layers of gesso. If you're using watercolour or gouache paint, prime with at least two coats of Watercolour Ground. Sand each coat of your primer with fine grit sandpaper between each coat.

When your primer is dry, you're ready to paint! If you want to seal your painting when it's done, choose a specialist varnish that's appropriate for the kind of paint you used.

Hanging your painting is easy. Using the appropriate fittings for the kind of wall you have, insert a regular screw into the wall, stopping when the screw head protrudes slightly. Line up the hole on the back of your panel with the screw (the hole should be slightly wider than the screw head) and hang!