Making Pigment From Plants

Creating Lake Pigment Paints

This is the process for making an insoluble colour pigment from a plant extract, which can be used to make paint by adding a binder such as gum arabic that sticks the pigment to the page, and a filler to hold the paint in solution such as water.

You can try this method with any plant: especially marigold flowers (yellow), dahlias (pink, purple, yellow, orange, green), and rose (pink, green), madder for a pink and Rosemary – yellow

  1. Source fresh or dried plant material eg. tagetes marigold flowers.
  2. Cover your plant materials with hot water. Simmer for 10 minutes. Strain the liquid in to a large bowl. Repeat this process with the same flowers three or four times, adding the liquid to the same bowl, until there is no more colour coming out. I suggest using small quantities of water each time so that you don’t end up with a huge quantity of liquid. Filter the dye bath to remove any plant material that might be in it.
  3. Measure out your aluminium sulphate: 10g/litre and soda ash: 5g/litre. I recommend that you wear a dust mask, gloves, and safety glasses. Make sure that the bowl is no more than half full, otherwise it may overflow. The mixture may fizz up. Add the alum to the warm dye bath. Stir gently. The alum will bind with the dye particles. Add the soda ash to the dye bath, stirring gently. It may produce a lot of bubbles. The soda ash causes the dye pigment to become insoluble in water and settle to the bottom of the dye bath.
    You may see a colour change, this can be dramatic, or it can be subtle.
    The soda ash will neutralise the acidity of the alum. You can check the pH and balance it out to neutral by adding either more alum (acid) or soda ash (alkali). Give the liquid a stir and then leave it for an hour to settle.
  4. The pigment will settle to the bottom of the container. Pour off the top liquid in to another bowl. Observe this liquid. If it is clear, you can discard it. If there is still colour on the liquid, you can add a desert spoon of aluminium sulphate and a desert spoon of sodium carbonate to extract more of the colour.
  5. You can flush water through the pigment to wash it.
  6. Pour the pigment that has settled in the bottom of the bowl through a coffee filter or in a sieve with a piece of cotton in it acting as a filter. This is a slow process. The pigment will stick to the filter, this is what you will use to make a paint or an ink.
  7. You can collect the pigment from the coffee filter or in a sieve. I like to leave the pigment to dry out for a day or so, I wait until the pigment is thick and gloopy but not completely dried out. I then use a knife or spoon to scoop out the slightly wet pigment.
  8. You will need to add a binder to stick the pigment to your paper. I use powdered gum arabic that I have rehydrated in two parts water to 1 part gum arabic. I add 1 part gum arabic solution to 1 part wet lake pigment. I test it out, and then adjust the consistency by adding more gum arabic, more of the pigment, or more water until I have the consistency I like for painting.
  9. Shifting consistency through pH. Try adding some acid to it, such as citric acid or vinegar- you may see a colour change. You may also find this turns your paint in to an ink as the acid breaks the lake shifting the pigment back in to a form that is soluble in water.
  10. If you want to create powder pigments or oil paints, rinse the pigments while they are in the filters with fresh water to remove impurities, and then dry and grind the pigments. You can then mix the pigments with oils, waxes, or other carriers.
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