Yellow pigments were highly desired in the Middle Ages. The color represented wealth, grandeur, and vitality. One of the more simple recipes for a vibrant yellow was orpiment, a rock that was crushed and watered to turn into paint. For the medieval artist, this sounded like a golden opportunity. However, these artists would soon learn that the fumes from this paint were poisonous and smelled horrendous. As the fumes came into contact with the artist, their skin would burn, resulting in a painful, excruciating death if ingested. Seeing as this is not ideal, medieval artists would soon prefer to create yellow pigments from the sweet spice, saffron, which we now know provides many health benefits.
Saffron was used to make yellow and gold-colored pigments and is sourced from the stamens (the male fertilizing organ) of crocus flowers.
Its yellow coloration is due to the presence of a carotenoid called crocin (another carotenoid, beta-carotene, is responsible for the orange color of carrots). The name Saffron in modern times, specifically, refers only to the stamens of the species Crocus sativus, but during the Middle Ages, other species of Crocus were used to source yellow pigmentation as well. However, Crocus sativus, cultivated mainly in Spain and Italy, resulted in the most vibrant yellows and was thus favored when mixing purely yellow pigments (Thompson 185). Saffron in modern times can be very expensive, due to the fact that its harvesting and processing has many steps that require human intervention, but during the Middle Ages it was about as costly as any other imported plant used for pigmentation.
Once the stamens of the mature crocus flowers are carefully harvested, they are crushed into a powder or left whole. The powder, or the whole stamens, are what would be traded and sold for the use of making pigments in the Middle Ages. To simply make a pure yellow, soaking a pinch of the saffron dust in glair (a medium made from egg whites) would be enough, and more could be added to increase the opacity and vibrancy of the coloration. However, it can also be made into ink directly, by boiling it in water with gum arabic until the stamens entirely dissolve/lose their color. For making dyes, heating saffron in a strong lye solution was also a relatively common medieval recipe (Cennini 29). If made with just saffron and glair, the mixture would need to be kept cool and exposed to as little air as possible to keep it from fading or spoiling.
Saffron tends to produce very pure, slightly golden yellows in most dilutions, but can be used to make more reddish yellows when concentrated. It was often chosen over other sources to make yellow, such as Lead, Realgar, and Orpiment, because it appears far more golden, although it can also be mixed with any of them to produce a more golden-colored version of those pigments (Medlej 65). When mixed with glair, it can be made highly translucent and used on top of other colors to add a yellowish-gold tint/sheen to them. Saffron yellows can and do fade over time, especially if diluted heavily to begin with.
In our class, we followed one of Medlej’s recipes (64) to make a saffron pigment using only small pinches of saffron (the whole stamens, not powder) and glair, without requiring boiling or heat. Isaac made glair at home the night before our first mixing day in class, and brought in a small jar of it.
We divided the glair into two roughly equal portions and added enough saffron that would be needed to achieve our desired opacity. We decided to aim for a glaze, rather than an opaque pigment, since we figured that would be easier to accomplish on our first try. One of the containers got two pinches of saffron, while the other received three. The scale our class was using wasn’t able to accurately measure the weight of small amounts, so we had to eyeball our measurements. For the container with the greater amount of saffron, we slightly crushed the stamens to potentially speed up the absorption process of the pigment into the glair base.
The container with the lesser amount of saffron was left to soak for the rest of the class period (45-50 minutes) in the sun. It did not noticeably change in coloration but began to smell awful (as expected of an egg product set out in the sun for nearly an hour). The other container was taken home and left sitting in a refrigerator for nearly 48 hours until the next time we met in class.
During the soaking process, the solution was slowly but surely darkening and turning more golden in color, as well as generating a white foam around the slightly-crushed stamens suspended within it. We believe this to be leftover foam from the glair-making process, as Isaac only let the glair “drain” for 10 hours.
Back in class, we finally tested the pigment, which flowed and stained like a watercolor, eventually drying and darkening to a bright yellow with darker edges. Ultimately, the result was not a glaze like we were aiming for, and not quite as golden as we expected, either.
After another day or so after application, the edges had darkened even more, to an almost-brown color.
Glaze of Glory
We made a second batch of saffron pigment for the day that the whole class tested their pigments on different substrates, this time using less saffron to hopefully make a proper glaze. We applied the result to the substrates (two different bonds of paper and parchment). We believe that the glair, which enhanced the paint’s viscosity, had a notable impact on the mixture’s capacity to adhere to the page. After a few minutes, it appeared that the intensity of the color varied according to how hard and how long the brush was applied to the substrate.
We also tried mixing our yellow with the other group’s pigments, pictured below. The azurite and cinnabar took the glaze better than the brazilwood and verdigris.
A closer look, with labels (Saffron soaked for 6-12 hours)
Overall, we learned a lot from this experience! Even though the steps were simple, it became clear to us that getting exactly the right color, opacity, and consistency would take a lot of practice to pull off (especially in larger batches), but that experience requirement would be more than worth it in exchange for such beautiful golden hues. If you have saffron, eggs, and some time to spare we encourage you to try a recipe out yourself!
Works Cited
Cennini, Cennio D’Andrea. The Craftsman’s Handbook. Dover, 1954.
KENPEI, https://upload.wikimedia.org/wikipedia/commons/5/5c/Crocus_sativus2.jpg
Medlej, Joumana. Inks & Paints of the Middle East: A Handbook of Abbasid Art Technology. Majnouna, 2021.
Thompson, Daniel V. The Materials and Techniques of Medieval Painting. Dover Publications, 2019
Featured Image Citation : CC BY-SA 4.0, <https://commons.wikimedia.org/wiki/Category:Saffron#/media/File:Saffron-pushal-zafaranic.jpg