blues
What is it? A European plant (isatis tinctoria), probably introduced to England in the Neolithic period. The plant contains indigo, which is extracted for dye or pigment.
How is the pigment made? Harvest the woad leaves in late June/early July. Put the leaves in a pan of rain water and heat for an hour. Cool the liquid rapidly and strain the leaves, which are then discarded. Aerate the liquid. Leave the pigment to settle, and then pour off the top two-thirds of the liquid. Top up and repeat until the water is clear. Dry the pigment in a shallow saucer.
Was it easily available in England? Yes. Planting woad seed is mentioned in an agricultural treaty from the tenth/eleventh century (see blog) and it has been identified in early medieval English manuscripts such as the Lindisfarne Gospels. It was easily available as pigment and dye as there is evidence of dye manufacture in viking York.
Is is safe? Yes. But always take care to wash hands after touching and avoid inhaling raw pigment.
Woad
Lapis Lazuli
What is it? Naturally occurring metamorphic rock (Na,Ca)8(AlSiO4)6(S,SO4,Cl)1–2. Found in Afghanistan, Russia and Chile.
How is the pigment made? According to Cennini's recipe, the rock is ground first. Then it is mixed into a liquid of melted gum and wax and moulded into a rod. After a time, soften the rod in a solution of warm water and lye. Keep pouring off the lye into several bowls, the lapis will fall to the bottom. The first bowls will yield the best grade.
Was it easily available in England? Yes, it has been identified in English manuscripts from the tenth century. It would have come from Afghanistan, and was possibly imported ready-made.
Is is safe? Yes. Traces of lapis lazuli have been found in the jawbones of twelfth-century women religious in Germany, who presumably were licking their brushes while producing illuminations. But always take care to wash hands after touching and avoid inhaling raw pigment.
What is it? A naturally occurring mineral made of copper (Cu3(CO3)2(OH)2). Formed in caves. It is often found with malachite, the other basic copper(II) carbonate mineral.
How is the pigment made? Take a chunk of azurite and grind in a mortar and pestle to a powder. Swill the powder in a lye solution then decant the solution into another bowl, keeping the azurite that sinks to the bottom. Keep decanting into bowls until the azurite residue gets lighter. The first pourings will be the best grade. Dry and mull –although not too hard or the blue will go grey.
Was it easily available in England? It seems to have become popular in England during the thirteenth century, eventually taking over from lapis lazuli by the late medieval period. It was probably imported from Germany or France.
Is is safe? Moderately toxic. Always take care to wash hands after touching and avoid inhaling raw pigment.