Tea and coffee contain natural pigments that you can use to stain paper and other materials to create different effects. Using diluted tea and coffee to make a simple paint or stain can create paintings that play with light and dark shading. Experiment with fruit teas, as well as the usual brown tea, to obtain different colours. Red-coloured fruit teas, such as strawberry and raspberry, make successful pigments.
Put a tea bag in a cup and pour hot water over so that it just covers the bag. This releases the pigment into the water to make a darker paint. Squeeze the tea bag and pour a small amount of the tea water into a section of your palette. Add double the amount of water to the same cup, stir the tea bag then pour some of the mixture into another section of the palette. This will be a lighter shade. Repeat these steps a couple more times, increasing the water each time to weaken the pigment. This will give you a range of shades to paint with.
Fill a cup halfway with hot water. Stir in a small amount of coffee granules and pour a little into a section of the palette. This will make a light coffee pigment to work with. Add a few more granules to the cup and pour more of the water into another section of the palette, making a darker pigment. Keep adding granules to the cup of water and pouring the results into the palette to get even darker pigments.
Go through each pigment in your palette and paint a sample line on a scrap piece of watercolour paper to show the depth of colour for each.
Lightly sketch the scene you wish to paint on the watercolour paper using the pencil. Begin painting the scene with the pigments in the same manner that you would a normal painting. Concentrate on the different shades to create contrasts in the painting. Use the sample lines as a guide to know which pigment strength to use and use a different brush for the tea and the coffee to avoid mixing.
Regularly wash the brushes in fresh water and dry them to maintain the pigment strengths.
You can use larger receptacles than a watercolour palette to store the paints in for pictures requiring a lot of tea or coffee paint.