There are lots of natural products that can be used to dye fabric. To make a natural dye and help your students explore how effective it is, boil a chopped red cabbage in water for 30 minutes, making sure you keep the water level constant. Cool and strain before the lesson. You will be left with a purple-coloured dye. Natural and synthetic fabrics will respond differently to the dye.
In teams, students should choose a material to work with. Cut the material into strips, measuring about 5 x 10cm. Each team will need six strips of untreated material.
To test the best way to dye the fabric you could choose the six different sets of conditions listed below.
Each team should use a fabric marker to mark their material with their team name, and set number 1-6. The first four sets can be done by the students, but sets 5 and 6 should be done by the teacher.
The material that has been boiled should be left to cool naturally.
Students should wear plastic gloves and aprons when handling the dyes and dyed fabric.
Remove each strip from its dye bath and rinse it in cold water. The fabrics should then be hung up to dry naturally.
Many dyes react with the fabric to form bonds that stick the dye to the fabric. The strength of these bonds determines how colour-fast the dye is.
To test the effectiveness of the dye, look at the depth of colour or test how fade-resistant the dye is when exposed to light or when washed.