Preparing the ground – Gesso

I have chatted at length about stretching paper and have still promised a post on my easy way to rule up for calligraphy, but today’s post is how to gesso a board for acrylic or oils. Working on a well-gessoed board is a delight and calligraphers who do drawn and painted lettering or brush lettering will love this as an alternative to paper. (b.t.w. Calligraphers, for lettering, Lascaux Acrylic is my favourite acrylic medium as it is so smooth and the pigments are fab. and the metallic pigments glow)

Now to prepare your ground for oils: There are many different grounds you can use. You can buy stretched canvasses – stretched with cotton duck fabric, pure linen, or el-cheapos in the pound shop. You can stretch your own canvasses or buy canvas stretched over board instead of a frame.

We are doing the least expensive ‘nice’ surface on hardboard which is archival and good quality. (MDF is fine for learning, but there are nasty chemicals lurking in the compound, so hardboard is really better.)

The finish can be textured with a bit of ‘tooth’ or smoothly and finely sanded, or even have a rough texture. I’m going to describe the slightly textured finish.

Materials
Large flat decorators brush, about 7cm wide
Ready-made Acrylic gesso (Any of the artist’s brand names such as Daler Rowney etc.)
or homemade gesso*
Medium sandpaper approx 100grit
3mm or 5mm MDF board
Latex gloves from somewhere like Lakeland

• It is worth laying the board on bricks to do the sides easily. I use a plastic cloth under the bricks to protect the table. I work superfast with a left hand gloved so that I can hold the board with one hand while I paint.
• Sand over the board lightly by hand to get rid of the smooth surface so that the gesso will have some ‘purchase’.
• Paint the edges first and make sure there are no thick drips on the two surfaces.
• Ist coat front: Thin solution of gesso mixed with about 1/3 water to penetrate.
• 1st coat back: Thin solution of gesso mixed with about 1/3 water to penetrate – to stabilise board
• 2nd coat front: Sand, lightly then: full strength gesso.
• Brush in well all directions. Check for globs on edges.
• 2nd coat back: Sand, lightly then: full strength gesso, to stabilise the board.
  
• Dry several hours
• *At this stage you can do two more coats with ready-made gesso or just one coat with home-made gesso – see recipe below.
• 3rd coat front: Sand lightly with medium sandpaper. Repeat as for 2nd coat.
• 4th coat front with ready-made gesso, if you didn’t switch to the home-made gesso: Repeat as for 3rd coat.
• If you want a very smooth surface you can use a finer grain of sandpaper.

Home-made gesso recipe for a short-ground gesso:
3 parts good quality artist’s white acrylic – I buy Jackson’s own brand.
1 part whitening – this is chalk.
Mix together and use. each time you use it you will have to stir it first. I decant some into a smaller container as it dries on the edges and falls into the mixture making lumps.
A short-ground gesso is slightly absorbent and the paint will dry more quickly.

If you like working on a toned background, you can rub some oil paints such as ochre or umber thinned with medium over the surface to break into the white. Use very little oil paint and dilute it well with medium and rub it on with a cloth. It is nicer when the background is not evenly toned but has a bit of life in it. You could even use a little diluted acrylic paint instead. If you work on a pure white surface the colour can be more scintillating, if it is roughly applied.

Fat over Lean theory : You can paint in oils over diluted oils (which has less oil and more turps) or over acrylic, but not the other way around. So you can’t paint in acrylic over oils because at some point the oil will rise to the surface and the painting will crack. If you make salad dressing, and visualise the olive oil floating on the vinegar, this will make sense!

Tips

• You can buy a sheet of 3mm mdf or hdf measuring 610mm X 560 and have it cut at the shop. I get mine done at Homebase. It will give you 8 small sheets of 22cm X 28cm which is a nice size for starting out.
• I do 8 boards at a time, and this uses 2.5 Tbs gesso.
• I prefer to do the brushstrokes in different directions so that the initial texture for the painting is not mechanical and evenly patterned. A roller will give a much more even texture, but if the paint is thick it can result in ridges. Even an electric sander won’t be able to remove the ridges.
• A new paintbruish may shed hairs. If there is a hair on your surface, flick it off (or pick it up) with the paintbrush.
• By decanting the paint into a smaller container you will accumulate less dried paint on the edges of your large container. These flake off and the gesso gets lumpy. I had to sieve my entire 5 litres to get rid of dried bits of gesso.
• Do the sides of the board first. Dip the brush and get the excess off on to the surface to be painted, then do the sides. This way there will be fewer globs on the edges. Globs are a nuisance when you want to frame your work.
• I wear a latex gloves because with all the stuff I do, my hands take a lot of punishment.
• 

Health and Safety: There are resins in mdf so it is advisable to wear a mask so that you don’t inhale when you sandpaper the boards. And you don’t want to be inhaling gesso dust either. This is very important for people with respiratory problems.