maya blue recipe

After discussing Indigo as Pigment, I’ve had a lot of requests to share the process for making Maya blue. This recipe is based on the research of Michel Garcia, whose Natural Dye Workshop DVD series I recommend. To make Maya blue pigment at home, only two ingredients and a few tools are required.

  • Botanical indigo powder: This can be store-bought or home processed, and must be thoroughly dry and finely ground.

  • Clay substrate: Sepiolite, palygorskite or attapulgite will absorb the indigo when heated. You can purchase small jars here, or larger amounts here. If your clay is granulated of foraged it must be finely ground.

  • Mortar and pestle for grinding: This must be dedicated to crafts only, never food.

  • Dust mask: These types of clay can be irritating.

  • Small pot: Likewise dedicated to crafting.

  • Mulling slab and muller: For extra finely grinding the finished pigment and mixing paint.

grinding sepiolite clay

grinding sepiolite clay

Make certain that none of your tools have any water on them, as even a drop will spoil the reaction. After finely grinding, weigh 10 parts clay and 1 part indigo powder. I have used 30 grams sepiolite and 3 grams indigo. Combine these in a small pot and heat over a medium low flame.

Over the course of a few minutes, you will see the two powders combine and turn a uniform blue color. At 356 degrees Fahrenheit the indigo sublimates to a gas, bypassing the liquid phase, and is immediately absorbed by the clay. Remove the pot from heat and allow to cool. The color will have a violet tinge when hot, but turn turquoise as is cools. You now have Maya blue pigment, indigo locked inside and stabilized by the clay.

maya blue recipe
  • A Weighed indigo and sepiolite

  • B Mixed indigo and sepiolite before heating

  • C Mixture after heating: Maya blue!

Maya blue pigment may be stored indefinitely. To use as paint it must be finely ground with a mortar and pestle followed by mulling with a binder to mix the paint of your choice. Check out Kremer Pigments and Kama Pigments course offerings and videos to learn how to prepare your own watercolor, egg tempera, or oil paints.

mulling maya blue watercolor

mulling maya blue watercolor

indigo as pigment

Straying a bit further afield from the recent posts on alum and the quantity of alum used in paper marbling, let's address the question obliquely raised in the last post on lake pigments:

Indigo is a pigment?

Many of us natural dyers are well familiar with the process of concocting an indigo vat and the working properties of indigo as a dye. It is truly remarkable that so many historical cultures throughout the world developed a practical understanding of the complex chemistry governing the indigo vat, leaving us with a wealth of cultural and artistic heritage centered on this beautiful dye. But indigotin, the indigo blue which colors fibers dyed in the indigo vat, is an insoluble organic compound and can be used as a pigment. It may be mixed with a binder for use as paint without going through the trouble of making an indigo vat. Let's review the process by which indigo is made:

  • Indigo precursors naturally occur in the leaves of an indigo-bearing plant. After harvesting, these precursors are converted by enzymatic hydrolysis to indoxyl.

  • When oxidized, two indoxyl molecules join with oxygen to form indigotin.

  • Indigotin is indigo blue! Indigotin is insoluble, and can be used as a rich navy blue pigment.

  • Natural dyers now mix up their indigo vats to reverse the process. To work as a dye, an antioxidant reduces indigotin to leuco-indigo suspended in water. Fibers lowered into the vat become saturated with leuco-indigo, which spontaneously oxidizes to indigotin when lifted from the vat and exposed to air.

It's quite the feat of organic chemistry, but the peculiar dual nature of indigo provides its distinction as an artists' material. Used as a dye, indigo's working qualities have inspired resist techniques in cultures around the world. After dyeing, the indigo is not chemically bound to fabric and can be abraded from it with much washing and wearing, giving us the particular worn-in look of denim. And because indigo is inert when oxidized, it has better lightfastness that other natural dyes.

grinding indigo pigment
mulling indigo pigment

Sources of indigo pigment

In medieval Europe, indigo was prepared as a pigment by skimming and drying the flower from the surface of a woad vat, called blue florie, or grinding white lead with imported indigo. Indigo was widely available, fairly inexpensive, and in common use as a workaday blue pigment. It is a strongly tinting, dark, and slightly greenish shade of blue. Indigo is certainly a regal dye, one of the few lightfast historical grand teints. But as a pigment, its lightfastness did not match the more permanent and expensive mineral blues.

For use as a pigment today, pure indigo can be finely ground and mixed as watercolor, tempera, or oil paint. If you're a dyer, you can use the botanical indigo powder you already have on hand. You can also purchase the genuine botanical pigment from Kremer,* from Cornellisen in the UK, or you can buy Genuine Indigo paint pre-made by a reputable paint manufacturer.

Synthetic indigo was formulated in the late nineteenth century and is chemically identical to indigotin. Slight color variations between synthetic and botanical indigo are due to additional organic compounds extracted from different species of indigo bearing plants, including the colorant indirubin, which influence the shade of blue. Either botanical or synthetic indigo can be used as a pigment, but not indigo dye sold 'pre-reduced.'

*or get sidelined by Tyrian purple, the other famous vat dye with similar chemistry

homemade indigo and maya blue watercolors

homemade indigo and maya blue watercolors

What is Maya blue?

Maya blue is an indigo derived pigment used by ancient Mayan and Aztec artisans to color murals and ceramics. This pre-Columbian azure colored pigment is so stable and lightfast it was long thought to have a mineral origin. It is made by heating a finely ground dry mixture of indigotin and clay, either palygorskite, attapulgite, or sepiolite, to 356 degrees Fahrenheit. At this temperature the indigo is sublimated as a gas and replaces water in the clay, becoming a stable compound. Once cooled, Maya blue pigment can be mixed with a binder and used in all sorts of applications. Given that Maya blue requires a small amount of indigo, is lightfast, and is a lovely turquoise shade, it is superior to pure botanical indigo as a pigment.

I have only found Maya blue pigment available from Rublev, but it is not a difficult pigment to make at home. I have small jars of sepiolite clay available in my shop, as it can be difficult to source.

How do indigo and Maya blue fare in paper marbling?

Below are the results of some preliminary marbling experiments with homemade indigo watercolor and Maya blue watercolor.

  • Top: indigo watercolor

  • Middle: Maya blue watercolor

  • Bottom: both shades of blue

  • Column A: no mordant

  • Column B: pre-mordanted with 1.5 teaspoons aluminum sulfate/pint water

marbling tests with indigo pigments

I did struggle with getting the Maya blue to behave, though it functioned well in previous trials alone and mixed with lake pigments. The indigo blue has a beautiful rich hue, and will be useful for mixing dark shades.

As you can see in the right column, the pre-mordanted paper takes a crisper print with less streaking. The question of mordanting for indigo pigments was raised in the wonderful book Marbled Paper: Its History, Techniques, and Patterns:

Why, it may be asked, can some colors (such as indigo) derived from non-metallic materials, seemingly be employed without the use of a mordant? The answer can only be advanced in stages. To begin with, indigo, like the lake colors, which it resembles in several ways, has a low specific gravity. Secondly, it is likely that in its earlier, unsynthesized state, indigo contained minerals and metallic traces. There is good reason to suspect that somewhere during its manufacturing process or final preparation, alum was added, because earths, presumably containing alum and mineral salts, such as chalk, were often added as extenders to cut costs. But, most of all, indigo (like a few other dye-bearing plants) was insoluble in water, and had the ability to fix itself to an organic fiber without the aid of a mordant.
— Richard J. Wolfe

We know that historical paint manufacturers (and maybe some today) stretched or lightened indigo with the addition of various earths, inadvertently making a paint useful for marbling without a mordant. My homemade indigo paint is concocted of pure botanical indigo powder, which apparently does not have enough trace minerals to work quite so well without the help of a mordant.

However, Maya blue is useful for marbling without a mordant due to the chalk in its formulation. It is a lovely (though faint in this test), stable color which European marblers never had access to until the recipe was reverse-engineered in recent years.

Update: After 1 month of exposure to direct sunlight, no fading has been observed in either indigo or Maya blue watercolor samples on unmordanted paper. Lightfastness concerns about indigo pigment can be reserved for very long term light exposure.

alum & lake pigments

In the last post, we discussed the quantity of alum necessary to marble with watercolor and acrylic pigments on paper. There is another class of pigments that can be used for marbling, and was historically an important source of particular hues. These are lake pigments, made from natural dyes. As both a marbler and a natural dyer myself, these pigments are of great interest.

What are lake pigments?

Natural dyes (with the exception of vat dyes including indigo) are water soluble. This means they cannot be used for marbling, as they simply dissolve into the size. In order to make these beautiful organic colors, many of which have no counterpart among mineral colors, useful for  marbling they must be converted into pigments. A lake pigment is made when dissolved dye is precipitated onto an inert substrate - often potash alum. The precipitate is then filtered, washed, and ground. For marbling it can be mixed or mulled with a binder, usually watercolor medium, and used like any other watercolor paint.

If you've ever used the all-in-one dyeing method of mixing mordant, dye, and fiber in one pot, you may have noticed some of the dye spontaneously settling to the bottom. This means the dye and alum have bonded together, making a lake pigment.

mulling watercolor

What role does alum play in lake pigments?

As we learned about alum, it readily bonds to dye molecules, making it a substrate well suited to the formation of lake pigments. Other mineral mordants can function the same way, such as tin and copper salts. Each of these mordant substrates acts to stabilize the dye compound, improving its lightfastness. And just as with natural dyes applied to fabric, the choice of mordant and pH can strongly affect the shade of a lake pigment.

The example below is a lightfastness test of homemade lake pigments( yes, I need to practice patience in grinding pigments). On top is madder lake with copper; below it is weld lake with a little indigo, mixed as watercolors. The left side was exposed to direct southerly sunlight for one month, and the results I think are quite promising. Unfortunately lake pigments suffer from a bad reputation because they are not as permanent as their modern synthetic replacements or mineral pigments. Some lake pigments are certainly fugitive, and care should be taken to keep artwork made with them out of direct sunlight. The most lightfast pigments are made from the most lightfast dyes, such as madder, buckthorn, and weld.

Lightfastness test of madder lake and weld lake. Left side exposed to sunlight for one month

Lightfastness test of madder lake and weld lake. Left side exposed to sunlight for one month

Marbling with lake pigments

Because lake pigments contain a mordant within them, paper does not need to be pre-mordanted before marbling! I have read this in multiple sources, and the test below confirms it.

  • A: Unmordanted paper

  • B: Paper pre-mordanted with 1.5 teaspoons alum/pint water

The mordanted paper absorbs the marbled print a bit more quickly with a slightly sharper quality, but this shows that pre-mordanted paper is not a requirement.

Lakes are prepared for marbling just like any other watercolor pigment: each color is thinned to a good consistency and mixed with the appropriate amount of surfactant. You don't need to go through the trouble of grinding your own pigments to enjoy working with lakes, any 'genuine' watercolor lake such as rose madder or carmine will work. It can be difficult to know just what manufacturers put in their paints, and whether they are synthetic pigments simply bearing the names of historical shades, so it's worth seeking high quality paints if you want the real thing.

If you are marbling with a mixture of genuine lakes and pigments from other/unknown sources, pre-mordanting the paper is advisable.

testing alum mordant with lake pigments

In addition to lake pigments, I've read that any genuine earth pigment may be used for marbling without a mordant, as earth pigments are composed of minerals. It is clear from natural dyeing that ferrous salts are a very effective mordant, so the iron present in earth pigments should work the same way. I hope to test this in future, and make a comparison of the lightfastness of these samples.

Update: After 1 month of exposure to direct sunlight, no fading has been observed in samples printed on mordanted and unmordanted paper. The alum and chalk present within the lake pigments appears to stabilize the dye colorants admirably.

Please feel free to contact me with any insights or sources for historical pigments!