Subtractively mixing opaque media
WORKING WITH COLOURS:
Exploring Mixing Processes
Explore the subtractive mixing process using pastels and acrylic paints.
Details:
All ages
Time: 20 minutes
Learning Outcome: Notice and describe the variety of greens produced by mixing various yellows and blues in different opaque media.
Colour Concept: In the subtractive mixing process, the final mixed colour depends on the components and the media used.
Part 1 Materials (Pastels):
Yellow and blue coloured chalk pastels (3 to 4 of each)
Instructions:
On a piece of paper, create a 5x5 grid of squares. Each square’s length is approximately 1-inch or 2.5-cm. Alternatively, use the template provided.
Across the top, fill in each square with a different blue coloured pastel.
Along the left side, fill in each square with a different yellow coloured pastel.
For the remaining squares, create a mixture from the blue pastel in the top row and the yellow pastel in the corresponding left column. You can overlay the pastel layers, and mix them with your fingers.
Notice and describe all the variations of colours you see.
Figure 1. Grid of mixed greens from pastels.
Figure 2. Try mixing pastels on your fingers!
Part 2 Materials: Liquid acrylics
Yellow, cyan, blue, black, white and magenta coloured liquid acrylics (at least 2 yellows and 2 cyan or blues)
Heavy paper
Brushes, cup of water, paper towels
Instructions:
Choose 1 yellow and 1 blue coloured paint, and place small amounts of each on your paper.
Next to these, place equal amounts of the same blue and yellow, and mix them together.
Using the same blue and yellow, create mixtures of varying proportions, and notice the varieties of mixtures you produce.
Choose a different yellow and/or blue, and repeat the exercise.
Mix variations of the greens, by adding black or white or other colours of paints to the mix.
Vocabulary:
Questions & observations:
Are the mixed colours as you expected?
How did you make the pale, dark and muted colours?
How do the mixed colours from the pastels and acrylics compare?
What’s going on?
In this exercise, subtractive mixing using opaque media occurs with mixed pastels or opaque acrylic paints.
The subtractive mixing process involves the mixing of colorants whose spectral characteristics selectively absorb (or subtract) different wavelength ranges from the illuminating light source, resulting in the perceived colour. By comparison, the simple additive mixing process involves the mixing of coloured light sources, whose spectral selectively add to each other to create the perceived colour.
Subtractively mixed colorants remove light, each with a different range of wavelengths from the same illuminating light source. The remaining light is reflected to our eyes, and our visual system interprets the light as the mixed colour.
Find out more:
See glossary discussion on the subtractive mixing process and a thorough discussion in comparative mixing.
Check out Peter Donahue talking about subtractive mixing
