I have been asked several times recently how to make a lake pigment. 

The following works for me, although other people may have their own preferred method.

WELD LAKE PIGMENT

100g chopped or powdered weld.

50g Alum potassium sulphate

25g Soda ash – sodium carbonate

Soak the weld in about 2 litres of water overnight. The following morning gently heat to a simmering point for about an hour stirring frequently. Strain/filter into a beaker with a cheesecloth. The strained plant dye can be reserved to be used again later to yield a paler shade.

Add the alum to the beaker and stir well to dissolve. Once dissolved place the beaker on a deep tray. Mix the soda ash in about 100ml of hot water. Slowly and carefully add this to the alum mixture – this will create a high effervescent – whisk well until the foam has subsided or when a pH of 7 has been achieved. Scrape everything from the side of the beaker as this contains lots of valuable pigment. This is The Lake Pigment.

The following day draw off as much of the surface fluid as you can with a syringe.

Filter the sediment through a coffee filter adding a little distilled water if very thick.

The next step is to wash the pigment to remove any residue colourant, alum or soda ash that didn’t  bind to the pigment.

Transfer the pigment to a fresh beaker using distilled water to rinse the filter paper. Add distilled water to the beaker containing the pigment and leave to settle overnight. Repeat the washing process a few times until there is a clear separation.

At this stage the pigment is clean and can be dried and then ground to a very fine powder.