tempera

So I spent some time working with the old “putrido” recipe described in this post.

First I made titanium white egg tempera by grinding egg yolk (with a little water added) to titanium white pigment. I used a frosted glass muller, grinding on a marble slab. Following the recipe, I made it stiffer than I would if I were going to paint with it in egg tempera. Then I used a palette knife to mix it in approximately equal parts with some tube flake white (Doak’s flake 1c). (I don’t work with lead white in powder form.) I mulled the mixture on the slab. As the recipe predicted, the paint instantly became very stiff—much stiffer than either of the two ingredients before mulling. The recipe suggests adding oil, emulsion, or water. I added more egg yolk (emulsion) until the paint became workable. I mulled for several minutes and transferred it to my palette. It was quite thick.

Then I made some burnt sienna oil paint by mulling in linseed oil. I tried making egg tempera by mixing egg yolk with pigment/water paste, but it was very thin. I added a bit of dry pigment. Then I followed the same procedure, mixing the oil paint with the egg tempera in equal proportions. Again, it stiffened instantly. This time I added a bit of oil and, when that didn’t do the trick, a little water. After mulling this mixture for a few minutes, I transferred it to my palette. Again, it was very thick.

Then I tried painting with it. The paint alone was unworkably thick and pasty. It mixed easily with water, however. I was able to paint loosely. It handled similarly to other tempera grassa recipes I’ve worked with when thinned with water. Easier to blend than egg tempera, but not so smooth as oil paint. I could imagine using this for a lean underpainting.

Conclusions:

• Overall, this was not a success. The paint is not manageable without a lot of thinning down. It is not superior to other recipes that are easier to make. On the other hand, this was my first time. Next time, I will experiment by adding more oil to the mixture. It should still be water-mixable even with considerably more oil than I used.
• This is time-consuming. It would only be worth doing if I could make up a palette of colors and get them to last for at least a week or two before becoming bad or, well, putrid. The recipe suggests a few drops of clove oil. That would preserve the egg yolk and act as a retarder for the oil. The problem, potentially, is that the clove oil would retard the drying of the oil component of the paint after it’s been applied to the painting. That might slow the process of applying multiple layers. Another possibility would be to add a few drops of white wine vinegar.
• In terms of time, this will really only work for me with tempera mixed with tube paint. I don’t have time to grind my own fresh oil paint routinely, although that would probably produce superior results.
• Thus, I need to learn how to make more workable paint, and learn to make it last.

Update

24 June 2008: Applied thinly, the paint was completely dry the next day. It definitely has potential, at least for underpainting.

Also of interest

• Making gesso (2)
• Tempera grassa 2 (0)
• Tempera grassa 1 (9)
• Keeping oil paint fresh (5)
• Doak’s cristallo medium (5)

Those who’ve been reading here for awhile or have delved into the archives know that I’ve sometimes experimented with a traditional painting medium called tempera grassa. TG was most commonly used in the 15th and 16th centuries; it represents a transitional medium between egg tempera and true oil painting. TG consists of pigment mixed with an emulsion of egg and oil. Since the 16th century, TG has been fairly obscure—the best recent example would be the 20th century Italian master, Pietro Annigoni.

In the 19th century (especially in Germany), painting recipes were developed that involved various combinations of tempera ingredients, often including some combination of egg white, whole egg, linseed oil, stand oil, dammar varnish, stand oil, and turpentine. You can find many such recipes on the internet with a few simple Google searches. I’ve usually avoided these relatively complex recipes in favor of simple emulsions of egg yolk (the traditional binder for egg tempera) and linseed or walnut oil, mixed with pigment/water paste.

Recently, I ran across a web reprint of Egg Tempera Painting, Tempera Underpainting, Oil Emulsion Painting: A Manual of Technique, by Vaclav Vitlacyl and Rupert Davidson Turnbull. Published in 1935, it is a compendium of various tempera techniques. One that caught my eye is a recipe they call “putrido.” Putrido is one name for tempera grassa (because it starts to smell bad after a few days). They say that this is based on a recipe from an old manuscript found in Venice. For all I know it’s what was used in the Renaissance.

Take whatever quantity of dry color you wish to prepare. Divide it into two equal parts. Rub up one part with yolk of egg only into a fairly stiff paste. Rub up the other part with sun-bleached linseed oil, to about the consistency of ordinary tube colours. (To save time or trouble, it is possible to use ordinary tube oil colours, but to be sure of your ingredients, it is always advisable to grind your own colour in oil.) The part that is rubbed up with oil may be slightly larger in quantity than the part rubbed with yolk of egg. Then take the two parts so prepared and grind them together, preferably on the marble slab. It will be found that when these two parts are put together, the resultant mixture will stiffen at once into a very stiff paste, too stiff to be easily rubbed. This may be softened down by the addition of either water, emulsion, or linseed oil. If you wish to use the Putrido in its leaner form, add either water or the emulsion (Medium Fat Emulsion), but if you wish to paint with it as an oil paint using oil as the medium, then thin it down with oil. In either case, add the water, the emulsion, or the oil very slowly, only a few drops at a time, until the paste becomes a smooth cream easily handled on the marble slab.

I find this to be pretty interesting. It is a recipe that is similar to what I’ve done before, is simple to make, doesn’t involve solvents, and uses egg yolk (rather than the white or the whole egg), with which I am more familiar. They suggest that adding a small amount of oil of clove will preserve the paint mixture and allow it to be kept for some time (although not indefinitely). I expect that storing them in a refrigerator, especially in warm weather, would be a good idea. The oil of clove would also act as a retarder for the oil component of the paint, causing to dry more slowly. That could be a good or a bad thing, but I expect one would have to wait between layers for the paint to dry. You could try to balance the retarding effect of the clove oil by adding a small amount of lead napthenate, but that makes for a more complex reaction than I am really comfortable with.

I’ll have to try this recipe soon. I have a large painting that I started in tempera and then stopped work on. It might make an excellent underpainting for this TG recipe.

Also of interest

• Tempera grassa 2 (0)
• Tempera grassa 1 (9)
• Ultramarine in tempera and oil (4)
• The Three Graces (0)
• The smell of earths (0)

Christina writes,

I am new to egg tempera and here is my question. To mix the pigment with the egg yolk do you have to use one of those glass grinders and heavy glass surface? In my effort to work without the grinder I bought some liquid pure pigment made by createx. It is a concentrated pigment dispersed in water. It handles well and the colors are great. I’m just wondering if I’m missing something. Is there any premixed pigment paste one could use? The only negative side in handling the pigments I have is that they are liquid and I can’t make them any thicker.

Egg tempera is very easy to work with. For most purposes, you don’t need one of those glass grinders, which are called mullers. I use my muller much more for making and mixing oil paint than tempera. In the old days, when pigments mostly came in the form of rocks, it took a lot of work to grind them down to a reasonably even particle size, and mulling was the last step in that grinding process. Nowadays, the pigment powders you can buy are almost always ground evenly and to the right size for making into paint. There is a school of thought that says that pigments need to be mulled in water in order to make sure that every particle is surrounded by water, without any microscopic clumps of particles stuck together. In theory, that makes sense. In practice, you just can’t tell the difference between tempera made using mulled commercial pigment and tempera made using the same pigment, but without all that work. Mulling pigment is kind of a pain.

Here’s what I do: wearing a dust mask, I transfer powdered pigment into a small glass jar (baby food jars work great if you first boil them to kill any residual bacteria). I then add some distilled water (which you can get cheaply from your local pharmacy). I take off the dust mask, put the cap on the jar, and shake hard for 30 seconds or so. The pigment and water are now mixed thoroughly. How much pigment and water to use? It’s not that important. Most pigments will eventually settle in the water to the bottom of the jar anyway, leaving clear water at the top, so they create their own pigment to water ratio. For those that stay in solution with water, any reasonable mixture will do. I shoot for a consistency between cream and ketchup. Every couple of weeks I need to check my jars and add water to those that are starting to dry out.

The pigment dispersions sold by some companies work just fine also. For some pigments they make particular sense. Ultramarine, for example, settles to the bottom of a jar of water and forms a hard mass that you have to dig out with a palette knife. An ultramarine dispersion is easier to work with. Titanium white gets kind of chunky in water and requires a lot of mixing. But most pigments work just fine as pigment pastes.

To make tempera, separate an egg yolk. I like to mix in a very small amount of distilled water to thin it down and then shake it hard in a small jar. I mix the yolk and the pigment paste in a ratio of about 50/50 (some pigments like a little more yolk, some a little less). That’s it; you have paint. You can test it by painting it thinly onto a sheet of glass. Let it dry and then scrape it off with a razor blade. Does it peel off cleanly? You have good paint. Does it flake off or break apart? You have too much pigment or too much yolk. With just a little practice, it’s pretty easy to make it right every time.

In comments, Mae writes,

i have just bought pigment powder and am preparing wood (with gesso) to make an icon type painting…can you give me any tips on mixing egg tempera…the type of oil etc.

Prepare pigments as follows: while wearing a dust mask, use a palette knife or spoon to transfer each pigment to a small glass jar (baby food jars work great if you first boil them for 20 minutes to remove bacteria). Add distilled water. Put the cap on the jar and shake. You now have a pigment paste. Take the mask off, since there isn’t any more pigment dust to worry about.

Separate an egg yolk into another jar. Add about a teaspoon of distilled water and mix. To make egg tempera paint, mix about equal amounts of the egg mixture with pigment paste.

This is classic egg tempera of the sort that is used to make ikons (I’m pretty sure about that, but I am no expert on ikon painting). You can add other substances to it (oils, resins, etc.), but I suggest you learn to paint with just yolk, water, and pigment before you try to experiment with more complex mixtures.

Have fun.

Also of interest

• Ultramarine in tempera and oil (4)
• The smell of earths (0)
• The classical palette (0)
• Tempera grassa 2 (0)
• Tempera grassa 1 (9)

The impression many people seem to have of egg tempera is that it is a fussy medium that can only be used in one specific style. I think that comes from early 20th century proponents of tempera painting such as Daniel V. Thompson. While his books are an excellent resource, his insistence that tempera should be used just as it was in 14th century Italy gives the impression that the medium is limited to very slow work using small brushes to make laborious hatching strokes.

That’s one way to paint in tempera, and one that every tempera painter should probably familiarize themselves with.

But there are really only three constraints on tempera painting:

• You need to paint on a rigid support, preferrably on traditional gesso.
• You need to get the right ratio of pigment to egg yolk binder when painting (you can then thin it as much as you want with water).
• You can’t paint with thick blobs of impasto.

That’s it. You can use thick bristle brushes if you want. You can use a well-loaded brush, drybrush, or even tilt the panel horizontal and paint with loose washes. Wet paint can be blended. You can apply layer after layer of glazing. You can scrape the paint back, apply it with sponges, paint with your fingers, or rub partially dry paint to create textural effects.

Tempera is not fussy.

Also of interest

• Ultramarine in tempera and oil (4)
• The Three Graces (0)
• The smell of earths (0)
• The most influential painter you’ve never heard of (2)
• The classical palette (0)

I’m working on fairly large egg tempera painting—24 × 18”. Certainly not enormous, but larger than I’ve worked in tempera before. There are some large gradations that I’ve been working over with a bristle flat. Whenever I teach a tempera class, I have to push the students to use a dry brush and not use glom it on like they did with poster paint back in the 4th grade. That allows many layers to be applied in one session.

For the larger passages, however, I have found myself working with a pretty wet brush. After a few layers, the paint feels moist. I sometimes use a hair dryer (held at a considerable distance to avoid cooking the yolk binder) to dry the surface and allow my to apply another layer more quickly. I’m finding that insufficient. The surface of the paint stays moist and the dryer doesn’t affect it, as if the multiple layers of paint are keeping a certain amount of water locked in lower layers that won’t be affected by just blowing air on the surface. I need to stop painting now so that I don’t start digging up previous layers as I add more paint. It should be OK to paint on again in a day or two.

Huh. Never had that happen before. I’ve encountered this when applying multiple layers of tempera grassa (egg-oil emulsion) but never before with pure egg tempera.

You can strengthen a tempera painting, by the way, by sitting it in a sunny window for a few hours. The actinic light helps to cure the paint. You can also gently polish the hardened yolk surface with a piece of soft cotton, silk, or cheesecloth. This makes the dried layer smoother and more accepting of paint; it also helps even out any differences in sheen caused by varying yolk to pigment ratios.

Update

6 February 2007 (the following day): the paint has fully hardened and is ready to paint on again.

Also of interest

• The most influential painter you’ve never heard of (2)
• Tempera grassa 2 (0)
• Tempera grassa 1 (9)
• Some more thoughts on egg tempera (0)
• Online workshop: Renaissance Italian painting (3)

Here are two swatches of ultramarine blue. The one on the left is in egg tempera. The one on the right is Doak’s ultramarine blue medium oil paint. Both are mixed with titanium white at the bottom. It’s not as obvious in this photo as it is in real life that the tempera is lighter and higher in chroma. A number of pigments, especially earths, are brighter in tempera.

Also of interest

• The classical palette (0)
• Pthalo pigments (9)
• The Velázquez palette (3)
• Online workshop: Renaissance Italian painting (3)
• Making gesso, part 2 (0)

I keep most of my raw pigments in small glass jars, mixed into a paste with distilled water. Did you know that earth pigments have a smell? Of course they do; when you mix them with water, you get a sort of mud, and mud has a smell. The earths have a deep, loamy smell that makes me think of the first artists painting brilliantly and expressively with ochres on cave walls.

Also of interest

• Ultramarine in tempera and oil (4)
• The classical palette (0)
• Tempera grassa 2 (0)
• Tempera grassa 1 (9)
• Pthalo pigments (9)

Before the 19th century, painters didn’t have to worry about selecting a palette of paints from a huge array of those available. There were only a few pigments available, so painters had to make do with what they could get. If you wanted an opaque red, you had vermilion and, well, vermilion. So you learned how to get everything you could out of that pigment. You didn’t complain that it was a bit too orange for your taste, because your choices were vermilion and nothing. In addition, you had a couple of bright blues (both of which were incredibly expensive), a couple dull blues, a transparent violet-red, a green that had to be used carefully or it would turn black, an orange, a dull-ish yellow, one white, some variations on carbon black, and some earth colors. That’s mostly it, and you only had that many colors if you could afford them and lived someplace where there was enough trade to obtain them.

Go to a museum some time and look at some paintings from the Renaissance. Notice any absence of color? Dullness? Inability to obtain mixtures that convey a sense of reality? Muddiness? Poor color harmony? Unrealistic flesh tones? No? Many of those paintings were done with six or seven total pigments. Not pigments carefully selected to create an optimal palette from among hundreds of colors available in in an art store, but six or seven pigments selected from maybe ten or twelve that the artist could get. And yet they made some of the most gorgeous paintings ever created.

If you like the way paintings from before 1800 look, one option is to select a palette of colors that replicates those available then. So here is a simple palette that is similar to what was available in Western Europe before the new synthetic pigments began to be discovered in the late 1700’s. (CONTINUED) ⇒

Also of interest

• Pthalo pigments (9)
• Online workshop: Renaissance Italian painting (3)
• Ultramarine in tempera and oil (4)
• The Velázquez palette (3)
• The most influential painter you’ve never heard of (2)

“Tempera isn’t hard. It’s just slow.”

—George Tooker

I’ve been playing a bit more with egg tempera lately, and remembering why I like it so much. I can understand why tempera went largely out of fashion in the 16th century: oil paint has a greater value range (because oil darks are darker than tempera darks), so much can be done with blending in oil, and oil paint is perhaps more resistant to damage (although tempera doesn’t crack and yellow as oil does).

Tempera, however, has its own properties to recommend it.

• Many colors have more chroma and delicacy in tempera than in oil. Ultramarine blue, for example, is lighter and more saturated in tempera than in oil—it’s like a different color. Earth pigments have a clarity and vibrancy that they do not have in oil. And earths that are barely distinguishable from each other in oil paint have very distinctive characters in tempera. Siennas, red ochres, yellow ochres, golden ochres, green umbers, red umbers, burnt siennas, hematites, malachites, and so many other earths have properties that cannot be fully explored in oil paint, but which really come into their own when tempered with egg yolk.
• In tempera, pigments do not loose as much chroma when mixed with white or black as they do in oil. Tints are less chalky and shades are less dull. In tempera, you can work with higher chroma without looking garish the way really intense oil paints do. That helps to compensate for the reduced value range and gives tempera paintings a sense of delicacy and refinement without dullness.
• In oil paint, you can glaze, scumble, and partially mix multiple colors to achieve interesting optical mixtures. In tempera, the closest you can come to that is the petit lac technique common in Greek and Russian icon painting: you put a wet puddle on a panel that is horizontal and use the brush to very gently spread the paint without breaking the surface tension. That results in interesting, slightly mottled surface effects. In tempera, you can also use layer after layer of crosshatching, weaving colors across and over each other, to produce subtle optical effects.

There are also ways to use tempera and oil together as mixed media. Tempera makes a great lean underpainting for oil glazes, and tempera can be painted into wet oil paint to create crisp details. I hope to explore some of these in the future to try to make use of the best properties of each medium.

If you have an interest in egg tempera, I can’t recommend The Practice of Tempera Painting by Daniel V. Thompson highly enough. It covers the preparation of supports and grounds, choosing and working with pigments, doing underdrawings, application of paint, and gilding. I would only note that (a) you don’t really have to grind modern pigments with a muller and slab; you can just put them in a jar with water and shake; (b) his list of pigments is a little dated; and © we now know that Italian tempera painters did not use a detailed underdrawing as a critical component of the development of a painting’s value scale. Other than those details, the information in the book is as useful today as it was when the second edition was published in 1962.

Also of interest

• The most influential painter you’ve never heard of (2)
• Tempera grassa 2 (0)
• Tempera grassa 1 (9)
• Online workshop: Renaissance Italian painting (3)
• You say “sfumah-to,” I say “sfumay-to” (0)

is a type of paint made by mixing pigment with egg yolk.* This week I’ve been working on an egg tempera study (several figures copied from paintings by Fra Angelico), to use as a demo piece for the Renaissance painting workshop I’m doing at Wetcanvas and for an egg tempera class my wife and I will be teaching at a Society for Creative Anachronism event this Saturday.

I hadn’t done much tempera in the last year. I forgot what a beautiful medium it is. The painting process is to apply many fine hatching strokes with a dry brush, building up value slowly in a manner similar to working with a graphite pencil. The result is unlike any other medium. At first it’s frustrating, because I make a lot of little mistakes. Drat! I have too much paint on the brush. Akk! There’s still too much paint. Gah! I’m painting over an area that’s still wet and the paint is coming up. If you are trying to build tone, you gradually weave strokes back and forth, back and forth. You get into a kind of mental zone and suddenly it looks exactly right.

I need to do more tempera painting.

*If you are unfamiliar with painting media, please don’t confuse egg tempera with “tempera” poster paints for children. Other than being kinds of paint, they have nothing at all to do with each other.

Also of interest

• The Three Graces (0)
• The most influential painter you’ve never heard of (2)
• The classical palette (0)
• Online workshop: Renaissance Italian painting (3)
• You say “sfumah-to,” I say “sfumay-to” (0)

I’m doing an online workshop over at the Wetcanvas forum on Renaissance Italian painting materials and methods. You can follow along here.

Also of interest

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• The classical palette (0)
• You say “sfumah-to,” I say “sfumay-to” (0)
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• The Flemish method (18)

may be Giovanni Bellini. He lived a very long and productive life, from about 1426 to 1516, during a time of enormous changes in Italian Renaissance painting. Many of his family were excellent painters themselves, including his father Jacopo, his brother Gentile, and his brother in law Andrea de Mantegna. In his early career he painted with the traditional medium of egg tempera, in the early Renaissance tradition. In the 1470’s, however, he began to paint in oil. Italians at the time were mostly trying to figure out how the Flemish painters did such amazing things with oil paint; much of their work was derivative. But Bellini, over time, began to use oil paint as a means of rendering light and shade in a new way. His explorations of light, color, and air were innovative. In essence, he created the Venetian style of painting. It emphasized such “modern” oil painting approaches as a preference for painting on canvas, much larger paintings, the use of toned rather than white grounds, little or no use of egg binders, less use of discrete layering (i.e., more direct, wet into wet painting), the development of the composition in the painting stage rather than painting within the lines defined by an underdrawing, the use of built-up paint (impasto) in combination with glazing to represent texture and form, thick lights and thin darks, the systematic use of hard, soft, and lost edges to describe form, and a generally looser application of paint.

The Venetian style became the primary style of oil painting, throughout Europe, for centuries; it encompasses a lot of oil painting even today. He is not the only one who contributed to the development of this style, but his were the core innovations. His students, Titian and Giorgione, continued to develop and expand on the ideas he had invented. It can be said that Rembrandt, Carravagio, Rubens, Velazquez, and pretty much every important painter up until the Impressionists, were painters in the Venetian style, developing and extrapolating on methods first introduced by Giovanni Bellini. And even impressionism could be said to be a logical extension and modification of the Venetian style using a more modern palette of colors. So it’s definitely worth checking out his work.

Also of interest

• You say “sfumah-to,” I say “sfumay-to” (0)
• Online workshop: Renaissance Italian painting (3)
• The Three Graces (0)
• The Flemish method (18)
• The classical palette (0)

Note: These two posts on making gesso have been consolidated into an article here.

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Making gesso

Measure the volume of the remaining glue and pour it back into the double boiler. You will be adding 1.5 times this volume of chalk or gypsum to make gesso. Do this gradually, gently dropping each spoonful into the liquid to avoid making any bubbles. Distribute the chalk/gypsum around the pan so that it the glue soaks into it. Once all of the chalk/gypsum is in the pot, give it 10 minutes to soak. Now take a brush and gently stir the mixture, again trying to avoid making any bubbles.

Applying gesso

For the first layer, spread it thinly over the surface of the panel, stroking back and forth in one direction. It’s not very opaque when wet. Let it dry’ this takes 10-30 minutes, depending on humidity and temperature (dry days are best for gessoing panels). You’ll know it’s dry when it feels dry to the touch and any grayish areas have disappeared.

If the gesso is getting thick, it means that it’s cooling off. Replace the water in the double boiler with new hot tap water.

You will apply 6-8 layers of gesso. Brush strokes in each layer should be applied at right angles to those of the previous layer. Each layer is best applied shortly after the previous layer has become dry. It’s best to apply all layers in one day, so that they will bond with each other. If you get cracking, that means that you’re applying the gesso before the previous layer has dried. More layers will fix this. If you get little pits in the gesso, then you’re painting with gesso that has bubbles in it. Let the gesso stand for a half hour before applying any more, then rub the next layer in with your hand.

Once you’ve applied all the gesso, let the panel dry for at least three days. You can clean the brush, pan, and anything else that got gesso on it in warm water.

Smoothing the panel

Start by using a metal file to chamfer all of the edges of the gesso, so that they are at a beveled angle inward. This protects against cracking, should the panel strike something (I’ve had this happen, and it’s very irritating).

To get the panel smooth, I like to use a sanding block, starting with 400 grit sandpaper and moving to finer grits at the end. This produces a beautiful, eggshell-smooth finish that is almost too beautiful to paint on.

If I’m going to be painting with oil, I like to apply a final layer of hide glue to the smoothed surface of the panel. Without that, the gesso is a bit too absorbent. For egg tempera or tempera grassa, plain gesso works great.

Also of interest

• The classical palette (0)
• Pthalo pigments (9)
• Online workshop: Renaissance Italian painting (3)
• Making gesso, part 1 (2)
• Ultramarine in tempera and oil (4)

Note: These two posts on making gesso have been consolidated into an article here.

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As I’ve noted before, the acrylic primer on prepared canvases or available in stores is usually labelled “gesso.” It’s not actually gesso and shouldn’t be labeled as such. For oil painting, I find real gesso to be a much better surface than acrylic primer. Egg tempera and tempera grassa should be used only with real gesso panels. Gesso should only be used on inflexible supports (i.e., panels), because it is too brittle for canvas and will crack.

Gessoing is easy and almost foolproof, but time-consuming. It takes an afternoon to gesso a panel. On the other hand, it takes an afternoon to gesso five, ten, or twenty panels, so it pays to produce them in volume. I generally invest three or four afternoons a year in making enough panels to provide me with a steady supply.

Here’s how to make and apply gesso:

Materials

Hide glue (often labeled “rabbitskin glue” whether it contains any rabbit or not). Most major art suppliers have this.

Inert white pigment. This is powdered chalk or gypsum. The marble dust you can buy in art stores is chalk. Plaster of Paris is cooked (anhydrous) gypsum, but I have found it too gritty to make good gesso. (The word “gesso” means “gypsum” in Italian, since that’s what Italians made gesso from. In Northern Europe, chalk was the traditional material). You can buy good-quality powdered gypsum from specialty suppliers like Kremer.

Titanium white pigment. This is optional. Some people like to substitute up to 20% of the intert white pigment in the recipe below with titanium white, for brightness. I haven’t found it worth the bother.

Panel. There are various materials you can use for panel painting. One good option is to buy hardboard at the home improvement or hardware store. You can buy it cheaply in 4 foot by 8 foot sheets. Get tempered hardboard 1/4 inch thick. The staff at the store will probably cut it to size for you if you ask. Other materials you can use for panel include medium density fiberboard (MDF) and actual wood planks. Wood panels of any size, however, is best seasoned for 1-3 years, with planing to size if it warps, after it has been cut.

Wide flat brush. A good house painting brush will do.

A double boiler. Or use one pan that can fit inside a larger pan.

Measuring spoons, mixing spoons.

Sandpaper. Several grits.

Preparing hide glue

Make the hide glue the day before you plan to gesso the panel. Hide glue normally comes in powder or granular form. Mix one part hide glue with 11 parts warm tap water. One cup makes about enough to size and gesso two 8 × 10” panels, depending on how many layers of gesso you apply. Stir the water/glue mixture for about five minutes, then let it sit for 6-24 hours or so. It will form a thick gelatin. If the weather is very hot (95 degrees farenheight+), it might not gel properly unless you put it in the refrigerator.

Preparing and sizing the panel

The edges of the panel should be smoothed with sandpaper or a rasp. Clean the panel with denatured alcohol to remove any trace of oil or other guck.

Now you want to coat the panel in a layer of hide glue. This is called sizing the panel because another word for hide glue is “size.” You’ll start by warming the glue to make it fluid. If you heat the glue too much, it will weaken the glue. As it turns out, hot tap water is about the right temperature to liquefy glue without damaging it. So fill the outer pan of your double boiler and put the glue into the inner pan. In about ten minutes, it will be about the consistency of milk (whole milk, not that low fat stuff). Brush the glue over the front, back, and sides of the panel. Give it a half hour to dry.

I generally add more layers of glue to the back. The reason is that the glue in the gesso on the front will be applying force to the panel. If the panel is large, this will noticeably warp the panel. So I generally add about four layers of glue to the back in order to counteract the warping effect that the gesso will apply to the front. This seems to help a lot.

Also of interest

• The classical palette (0)
• Pthalo pigments (9)
• Online workshop: Renaissance Italian painting (3)
• Making gesso, part 2 (0)
• Ultramarine in tempera and oil (4)