Betsy Porter at work in her home studio area
Studio Tips For Egg Tempera Iconography
While working on your icon, set it flat on a hand towel to protect both the icon and the table. When packing it up, wrap it in the towel. Then put the bundle in a plastic bag inside a tote bag. If leaving an icon in place overnight, cover it with another towel.
You will be working with very small quantities of pigment. Take it from the container using a small flat pointed tool, such as the smallest size palette knife from the art supply store.
When mixing colors, you will need to handle small amounts of liquid egg tempera base and distilled water. Use an eye dropper for each container of liquid.
All paint must contain binder, which for egg tempera is the egg yolk. Combined with pigment, it will gradually cure and harden into a durable paint film. Do not mix paint with pigment and water alone!
After mixing paint, test it on lined white paper, to see how well it covers the lines. Use the same brush stroke that you will use on the icon - usually small wet circles. (This is especially important with floats, which should be very dilute.) When you are satisfied, check it again on an inconspicuous part of the icon.
Avoid spills! Pigments, egg tempera base, oilfa, liquid bole, and even water can make nasty messes that are time-consuming to clean. Get in the habit of replacing lids promptly, and check them before packing up.
Made a mistake? Remove fresh paint promptly using a Q-tip dipped in water and then blotted on your towel. For larger areas, use a damp cotton ball. Rub gently; do not scrub! If the paint has cured, then paint over it.
Small quantities of paint may evaporate more quickly than you can use them. Reconstitute thick paint using egg tempera base, not water. If leaving your paint for an hour or two, add a drop of egg tempera base, and cover your palette with plastic wrap or with another palette.
Store egg tempera paint overnight in the refrigerator, covered with plastic wrap. Do not store over 2 days.
Egg tempera has to cure or set up, so it is best to allow curing time between layers. Let your highlights cure overnight, and preferably longer, before you "float" over them with dilute color.
If conditions permit, work on two or more icons during the same session. Then the egg tempera will have more cure time between applications.
When cleaning up, wipe your palette well with paper towels before washing, to minimize the pigments and bole going down the drain and potentially clogging it. Mineral pigments and bole are not biodegradable.
Take good care of your beautiful natural-fiber watercolor brushes! Don't leave them nose down in the water. Swish in water to rinse well, then remove remaining paint by wiping with a tissue or towel. Let them dry flat on your towel between uses. Tilt nose down slightly so water will drain out of the metal ferrule.
THE RULING PEN AND ITS USES - A ruling pen is a drafting instrument, intended to quickly make precise ink or paint lines of even width. Many years ago in architectural school, we students were expected to make presentation drawings of our building designs, using the ruling pen to draw with indelible black India ink on white boards. Mistakes were not easy to erase!
The ruling pen tip consists of two flat parallel prongs, held in place by a screw which can be tightened or loosened to adjust the width of the line. Don't let that little screw get lost! Some compasses come with a ruling pen tip as well as a pencil tip.
To fill the ruling pen with liquid paint, fill a No. 2 brush and touch it to the space between the prongs, working from the side of the pen. The pen will hold about two brush-fulls of paint. No more please - because an over-full pen may suddenly drop a mess of paint on the surface of your board.
Practice on paper, to get the paint flowing and to make sure you like the line width.
The ruling pen starts and flows most easily if held at an diagonal to the surface - not straight up and down. If you have difficulty getting it started, touch the tip with a damp Q-tip or your slightly wet finger. Once the pen flows, you can just drag it rapidly along in its path until it runs out of paint and has to be re-filled.
Work quickly! Don't let the paint dry up in the pen. Wash the pen promptly after you finish using it.
Use your ruling pen with a regular handle to make straight lines, with the help of a ruler or straight-edge. To avoid smears from the pen, the edge of the ruler should be slightly raised above the surface of paper or board.
Use your ruling pen compass to make circles, such as the red circle around the halo. Before loading the pen to make the circle, establish the center and radius of the halo. Make a small indentation for the compass point, and set the compass to the desired radius. Fill the pen and quickly make the circle, tilting the compass as shown.
Paint flows quite thickly from the pen, and may take up to 30 minutes to dry. While the paint is drying, avoid other work near the line, so you won't smear the paint.
Keep a box of tissue and a slightly dampened Q-tip nearby, to clean up quickly in case of mishap.
TRUE GESSO By Patricia K. Kelly
Gesso is a mixture of whiting (calcium carbonate), white pigment, and rabbit skin glue. It is the traditional ground, or paintable surface, for wood panels employed in egg tempera and encaustic painting. Commercial ready-made gesso is acrylic-based and non-absorbent, but egg tempera and encaustic require an absorbent, rigid, dimensionally stable surface; typically a wooden board or panel covered with several layers of true gesso, composed of all-natural ingredients.
Gamblin’s Traditional Gesso and Fredrix’s Gesso Ground Dry Mix produce pre-mixed packs of dry gesso, available at Utrecht and other art stores. You just add water and follow the directions. If you’ve never prepared gesso from scratch, I highly recommend these dry-mix options. They are pretty good and convenient, because you don’t have to source the ingredients and fiddle with measurements etc.
Preparing your own gesso panels can be fun, especially with friends, and definitely heightens the painting experience. Gesso is tricky! Results can be unpredictable, because you’re working with the idiosyncrasies of animal and mineral products, but good materials and patient observation can yield good results.
My recipe is not scientific, and I cannot guarantee your results. However, this is the most straightforward recipe I’ve used. It’s based on volume measurements; one volume measure of glue size mixed with two volume measures of white filler. I normally prepare enough to cover 5-7 panels with 6-8 coats of gesso. You might prefer to start with just one panel. Scale the volume measure down to one cup.
MATERIALS
- Rabbit skin granules
- Whiting –big bag
- Titanium white dry pigment – 2 pounds
- Bulk size empty tomato can
- Double boiler
- 2-ounce empty tin
- 32-ounce empty plastic yoghurt container
- Wooden spoon
- Large sieve
- Dust mask
- Goggles
- Two 3-inch flat brushes, one for size, one for gesso
- Plywood panels – furniture grade birch, with edges sanded; or wooden icon boards, available without gesso from www.iconboards.com and other suppliers.
METHOD
PRELIMINARY SIZING; prime your panel with rabbit skin glue to seal the surface, to prepare it for application of gesso.
- 1x volume measure of rabbit skin granules– I use a 2-ounce tin as measure
- 10x volume measure of water. Mix granules and water together in a heat-proof container, and leave to soak until granules swell up. This can take an hour; or much longer if you’re working in a cold room.
- Place the container into a large saucepan of water and heat the size until it dissolves. Do not boil. Then allow the glue to cool; and put it into the fridge.
- Test for texture – as glue chills, it should acquire a crumbly Jello-like texture when you stick your finger into it.
- If it’s rubbery, it needs more water. Re-heat, adding a little more water.
- If the size doesn’t solidify to crumbly texture, add extra rabbit skin glue granules, but soak granules first.
- Apply one coat of warm (not hot) glue size to front sides and back of panel. Let panel dry overnight, and do not dry in direct heat.
PREPARING GESSO
- Wear dust mask and goggles.
- Fill empty 32-ounce yoghurt container with whiting; then carefully sieve whiting into heatproof tomato can.
- Fill 32-ounce yoghurt container with half whiting and half titanium white pigment; then sieve into can.
- Stir to distribute whiting and pigment evenly.
- Slowly add cold water whilst gently stirring. Add just enough water to produce a smooth, thick paste.
- Cover the container and set aside for several hours or overnight.
MIXING AND APPLYING GESSO
- Prepare fresh glue size, enough for your chosen volume. Mine is the 32-ounce yoghurt container.
- When size is still warm, slowly add volume measure to the tomato can whilst stirring gently.
- The mixture should now have the consistency of cream with no lumps. It’s vital to add the glue slowly; otherwise you’ll get lumps.
- As gesso cools it jells, so apply it warm. Place can in double boiler half-full of cool water on low heat. Do not overheat gesso, as overheating produces air bubbles in gesso. Ideally, get gesso to blood temperature, and do not stir vigorously.
- Apply first coat to front, back, and sides of panel. Use wide brush. Don’t go over your brushwork. The gesso will look streaky, that’s OK. That’s why you build up the surface in layers until it evens out.
- When water has evaporated from the surface, apply the next coat. Each coat needs to be laid at an angle to the underlying coat, so that the gesso has a better grip. Make sure water has evaporated before adding the next coat.
- Do not try to accelerate the drying process. In cold weather, gesso will take longer to dry.
- Stir gesso gently before each new coat, as the mixture can sink to the bottom of the can. If the gesso thickens, either it’s too cold or it needs a little more water.
SANDING AND FINISHING
- I don’t recommend sanding the gesso panel between coats. Wait until the following day after it’s had a chance to dry out.
- Sand with 400 wet/dry fine sandpaper to remove brush marks. Wear dust mask and goggles! Work outdoors if possible.
- Finish off by gently polishing the surface with slightly damp soft, fine white linen cloth.