Lake Pigments

A solution of dye, alum and soda ash in the process of precipitating. The liquid is seperating from the pigment. The dye is a bright reddish pink color. The lake pigment filtered on coffee filters, still wet. It has a thick consistency and is adark red pink color A coffee filter covered in dried pinkish red pigment A small mortar and pestle filled with finely ground pigment. The pigment is a pinkish red color.

A lake pigment is a water insoluble pigment created by precipitating water soluble dye with alum and soda ash. This is one way to recycle used dye baths made from natural dyestuff.

Once transformed into a pigment, it can be used as a base for making paint, a split lake dye bath, or any other application in which you use dry pigment.

Basic Recipe for a lake pigment:

  • Materials needed: Funnel, coffee filters, clothespins, dye bath from plant material, aluminum sulfate (also known as alum), soda ash, tall vessel, some jars for mixing.

  • Safety Considerations: Alum is considered a food safe additive. Soda Ash however is caustic to skin and eyes. I recommend wearing kitchen gloves, a dust mask and safety goggles at minimum when handling it.

  • For approximately every 1L of dye bath you will use 10g of alum and 5g of soda ash

  • If the bath is still warm you can add the alum directly to the dye bath. Otherwise mix it with hot water beforehand and then stir it in. Stir until dissolved.
  • Stir in the soda ash in the same manner but add it more slowly. The soda ash with interact with the alum by neutralizing the acid with bubbling, so make sure you use a vessel with enough room for this.

  • Let the liquid sit for a couple of hours or overnight. You will see the dye precipitate as the dye molecules bind to the alum and become water insoluble. When the dye has settled to bottom pour off as much off the top as you can without disturbing the settled pigment.

  • Set up a funnel above an empty jar, or alternative I’ve used a pour over cup that I only use for this purpose. Double line it with coffee filters and clip the filters to the edge using clothespins. Slowly pour the rest of the liquid through the filter. If you have a lot of liquid you might need to wait for the first batch to complete and use more filters.

  • It will drain slowly but eventually you should be left with a sort of sludgy looking goop in the filter and most of the liquid drained through to the jar. Unclip the filter and taking the top one tear it so it lays flat and place it on some layers of paper towels.

  • Leave it to dry in a dark place, especially if you don’t know the lightfastness of the dye stuff. It will shrink and crack as it dries.

  • When fully dry scrape into a mortar and pestle and grind as fine as possible. Store in a small container away from direct light.