Venetian Red The name Venetian Red (a variety of PR102) can apply to a lot of different shades of natural red earth, and unfortunately the name space is not standardized. Usually Venetian Red is rather opaque, and is a nice warm light red. Some versions are deeper, but we chose one of the more chromatic natural red-orange earths which happened to be by Rublev. In particular, Rublev's paint is quite loose due to lack of additives, and so we had to put it on a paper towel before using it as there is some oil separation. This is not necessarily a bad thing, just something to be aware of. The Rublev has a pronounced red-orange note.

Transparent Yellow Oxide For a more traditional palette, one could use Yellow Ochre, PY43. For the more modern Transparent Yellow Oxide we chose the Williamsburg version. Williamsburg makes several PY42 varieties. This one is deep in masstone and chromatic in tints. It has a finer grain than some of their grittier earths.

Ivory Black Normally, we would advise some caution when painting with Ivory Black, especially if one is making a layered painting. It can exhibit drying problems and is not really advised for use on the lower layers, and we have heard anecdotal stories of problems when used liberally in masstone. The black in this palette functions a bit like a blue and adds some much-needed coolness. The Ivory Black, PBk9, was by Michael Harding.

Titanium White For our tinting comparisons we usually use Williamsburg, but for this particular palette we chose Isaro's Titanium White. The tube is quite narrow and has its own charm. For a more traditional palette, Lead White could also be used, but of course it is very toxic, so for this we opted for titanium.

For this palette, in addition to the descriptions discussed above, we've rounded up some additional choices for colors as many brands would probably work.

In our opinion, it would be nice to have a range of red earths for the red notes and not just one. Spurgeon also suggests modifying the red a bit, see his book for more.

This is a super warm palette. Spurgeon also recommends cooling off and deepening the venetian red a little with just a touch of Mars Red or even a crimson. The Venetian brings some real power in the dull oranges, however its masstone is not super deep, so richer reds would be a challenge unless the crimson note were added. So while this is technically a three color (plus white) palette, he recommends modifying the red into its own blend.

To choose a good basic Venetian Red, we would look for one marked PR102, only because we like the qualities of the native earths for the midtones of portrait work.

For the yellow note, a traditional yellow ochre may give a slightly duller and more semi-opaque midtone treatment for the yellow notes. Genuine Yellow Ochre, PY43, is generally not capable of the depth of Transparent Yellow Oxide, aka Mars Yellow, PY42. In terms of evaluating the palette on the basis of historicity or antiquity, Transparent Yellow Oxide PY42 may not be as far afield as it may seem. A good Mars Yellow may have been close to some of the most prized ochre samples of yesteryear, that is, if someone had a particularly dark, pure, transparent sample of native earth. The particle sizes on modern Mars Yellows varies a lot, so again, using a handful of earths would be nice. Since we only chose one, we picked one that has a fairly fine grind.

Honestly we had not expected to encounter surprises with Ivory Black. Michael Harding's version siezed up a bit (more on this below) when we added chalk. A good Ivory Black would be one that is a single pigment (e.g., we noticed Rembrandt's is a blend).

For the white pigment, we chose Titanium White. Lead White would give warmer mixes and have a different effect. To choose a good Titanium White, we would recommend avoiding Zinc Oxide (PW4) in the blend, as the percentages of zinc are not usually disclosed by manufacturers.

What came before the Zorn palette? Well probably the Tetrachromatikon. This palette made of earths has a lot in common with Zorn. Earths would have been readily available wherever ochres are found (yellow ochre can be made red by applying high heat, called calcining). Yellow Ochre or Yellow iron oxide can be used as is, and Natural Red Earth or red iron oxide also occurs naturally. The Bone Black would have been achievable as well as Vine Black. In antiquity it is quite possible the red would have received an upgrade in the form of genuine cinnabar, vermilion, or red lead, which are toxic. As oil painting itself is a later development, Chalk seems to have been used at different points throughout the history of easel painting, and chalk is also naturally occuring.

Modern upgrades to our Tetrachromatikon include the Synthetic Yellow Oxide or Mars Yellow for a bit of a chroma boost in the yellow oxide department, as well as Titanium White.

Zorn takes the Tetra a bit further in the reds, with the incredible punchy-yet-lightfast Cadmium Red. Side-by-side the Tetra looks muted and almost reserved compared to Zorn.

Rembrandt added chalk. Need we say more.

Spurgeon goes into great detail about a lot of fascinating modifiers for paints, and in a further section on something he calls the Predimensional Palette, he discusses adding chalk to the basic colors of a limited palette. We felt that addition was appropriate for the Tetrachromatikon palette, as many of the painters from times past may have modified the colors with chalk. So yes, it is technically another pigment (and so maybe our three colors plus white are actually four). However if a person is painting with certain brands of paint, we would argue that chalk is already in that three color palette anyway.

In regard to the many mediums in Spurgeon's book, we like to keep it simple with this old standby- just chalk and linseed oil.

A lot of modern brands may already include chalk as it's a common filler or extender. So here, we are basically making our own extender. Some commercial extenders have a little something extra besides chalk.

Chalk may yellow or show the yellowing more as it's somewhat colorless in oil, so as the paint film ages and the linseed oil yellows, it may show through more. Also as a health and safety note, don't breathe the dust. It's also important not to go too overboard with chalk as far as the percentage added to the paint. However, making one's own chalk putty extender blend is super fun.

We didn't expect to have to find other varieties of Ivory Black to test for this project. As mentioned earlier, the Michael Harding had an unexpected behavior when mixed with chalk. The Vasari was fine and so was Rembrandt.

Before we added the chalk, the Michael Harding was fine. However, since we wanted to work with the chalk, we had to opt for Vasari or Rembrandt. Both of the latter kept their expected paint consistency after the chalk was added.

As a heads up the Rembrandt is actually a blend with Ultramarine blue.

Beyond the more harsh, elemental colors in the palette, we found portrait strings were well within reach. Hints of crimson may be missing but we decided to leave those out for now as we wanted to explore the most limited version of the palette. This is where a Mars Red or a modern crimson could be added. The purple color beneath the piles of paint is not part of the limited palette, but rather was from another painting session.

Perhaps for many reasons this basic palette has endured through the years. One is the accessibility of the materials, but also their versatility. While some painters prefer to use higher chroma colors, this gamut of four colors covers many mixing targets for realism. Tad Spurgeon graciously made his book free for painters to read here.

Thanks for joining us, and Happy Painting!

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