What is it? A mineral made of hydrated calcium sulphide (CaSO4·2H2O). Can be mined from many places, including England and Ireland. It has been used as a plaster since the late Predynastic Egyptian period (c. 3200–3100 BCE).
How is the pigment made? Ground down as is and mixed with a binder.
Was it used in English manuscripts? Yes, mostly mixed with other colours to bulk up more translucent paints, or to lighten then.
Is is safe? Mostly, but can irritate nose and throat if breathed in.
What is it? A soft limestone made of calcium carbonate (CaCO3). It's made of the calcite shells of compressed plankton, formed deep in the seabed during the Cretaceous period (99–65 million years ago). Easily visible today in our landscape e.g. the cliffs of Dover. Can be mined above ground and underground.
How is the pigment made? Easily ground into a fine powder in a mortar and pestle.
Was it used in English manuscripts? Yes, like gypsum it was mostly mixed with other colours to bulk up more translucent paints, or to lighten then.
Is is safe? Yes, but breathing in the dust for prolonged periods can cause respiratory irritation.
What is it? Like chalk, eggshells are made mostly of calcium carbonate (CaCO3).
How is the pigment made? Make sure you have white eggshells, as per the medieval norm. Remove the membrane from the inside shell and crush into small pieces. Grind to a fine powder in a mortar and pestle.
Was it used in English manuscripts? Chalk has been identified in many English manuscripts, but it's not clear where the calcium carbonate has been sourced from.
Is is safe? Yes, but avoid excessive inhalation.
What is it? Can occur naturally as a mineral, but usually made artificially. It is lead carbonate 2PbCO3·Pb(OH)2. It has been used since Classical times as the process was mentioned by Theophrastus (c. 371–c. 287 BCE) in his work On Stones.
How is the pigment made? The same initial process as red lead. Sheets of lead are placed in a vessel with vinegar or urine, sealed shut and placed somewhere warm. After a few weeks the vessel is opened and the white accumulated on the lead is scraped off.
Was it used in English manuscripts? Yes, lead white was used all through the medieval period.
Is is safe? No. Now a banned substance in the UK. Wear a mask, gloves, and eye goggles in a well-ventilated area if handling the pigment.