tempera grassa

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)
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• The Three Graces (0)
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The acrylic primer on prepared canvases or available in stores is usually labeled “gesso.” It’s not actually gesso and manufacturers shouldn’t call it that. 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 inert 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, are best seasoned for 1-3 years, with planing to size if it warps, after it has been cut to final size.

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

A double boiler. Or use one pan that can fit inside a larger pan. I use an empty tuna can to support the small pan in the large 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 Fahrenheit+), 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 with hot tap water 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.

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 the first layer of 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. Cennino, a 15th century Italian artist and writer, suggested rubbing the first layer in with your hand rather than spreading with abrush. That’s messy, but works just fine and may improve adhesion.

If the gesso in your pan is getting thick, it means that it’s cooling off. Replace the water in the double boiler with new hot tap water. Don’t overdo it; this is usually necessary only once every 30-60 minutes or so.

Applying the rest of the gesso

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 with a large panel that I put a lot of work into, 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. Others use a thin layer of shellac or varnish to reduce absorbency; I haven’t tried that.

For egg tempera or tempera grassa, plain gesso works great.

Also of interest

• Question about panels (0)
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• Ultramarine in tempera and oil (4)

(First post on tempera grassa here). For some examples of great modern (20th century) paintings done in tempera grassa, check out the web page on Pietro Annigoni (1910-1988) at the Art Renewal Center.

Tempera grassa paint is a little like egg tempera (if you’ve tried that) and a little like oil paint, but mostly it is its own beast. It is much easier to control tempera grassa if you paint in thin layers and have relatively little paint on the brush when you make a stroke. It is, however, more flexible in application than egg tempera, and allows much more blending and re-working of the paint. To adjust the consistency of the paint, you can add as much water as you like, so long as the ratio of medium to pigment is correct. You can apply thin washes or heavy smears of oil-like paint. Never apply thick blobs of paint (impasto) as it can crack as it dries.

Small and medium-sized sable or soft synthetic brushes are best. Firmer bristle brushes can also be used—a bristle brush holds more paint and is good for initial lay-ins. Be very sure to clean your brushes afterward, as the oil will take its toll on them if you are not careful. For cleaning, I’ve had good luck with wiping brushes first with cheap linseed (not vegetable) oil, then washing very thoroughly with soap and warm water.

The paint will quickly dry on the palette if it is not kept moist (a spray mister is good for this). After an hour or two, the paint is more difficult to work with; scrape it off and make a new batch. Working with tempera grassa will be frustrating until you come to understand the process by which it dries. Because it is composed of substances that dry at very different rates, the paint goes through multiple stages as you paint. By keeping these stages in mind and learning to work with them instead of against them, you will find that tempera grassa is extremely flexible, in some ways like a water-miscible oil paint. (CONTINUED) ⇒

Also of interest

• Tempera grassa 1 (9)
• Online workshop: Renaissance Italian painting (3)
• Three ways to use oil painting mediums (0)
• The most influential painter you’ve never heard of (2)
• The classical palette (0)

Tempera grassa was a common painting medium in the 15th century. Since then, not so much (though with a few notable exceptions). It’s an interesting medium to work with.

Tempera grassa is an emulsion of egg and oil (an emulsion is a liquid in which tiny drops of another liquid are suspended). Egg yolk is a natural emulsion that incorporates oil into its makeup fairly easily. You are already familiar with an egg-oil emulsion—it’s called mayonnaise. Tempera grassa is essentially mayonnaise made with a drying oil such as linseed or walnut.

To make a simple kind of tempera grassa, separate an egg yolk and put it into a small cup. Measure the volume of yolk, then measure out the desired volume of oil. Add just a few of drops of oil to the egg, mixing thoroughly as you do so. Add a little more oil and continue mixing. Repeat, adding oil a few drops at a time, until all of it has been blended in. (CONTINUED) ⇒

Also of interest

• Tempera grassa 2 (0)
• Online workshop: Renaissance Italian painting (3)
• Three ways to use oil painting mediums (0)
• The most influential painter you’ve never heard of (2)
• The classical palette (0)