Generously cover your work surface with a drop sheet or newspaper, then place your canvas in the middle of covered area.
Break 6 crayons of like colours into small pieces and place in heatproof jug or bowl. Wearing gloves, use hairdryer or heat gun to heat up crayons until they start to melt. Alternatively, melt crayons for 15-second intervals in microwave.
Carefully pour melted crayons onto canvas in desired position, using spatula to help remove all the wax from jug or bowl. Using hairdryer or heat gun, further melt crayons and use the hot air to move them about canvas to create interesting patterns. Keep distribution of heat even so you don’t burn the wax and aim to keep wax coverage relatively thin as thicker wax may crack.
Repeat Steps 2-3 with new batches of crayons until your whole canvas is covered, blending batches of colours with hairdryer or heat gun. Remember to use complementary colours that will blend well together (choose 3 or 4 side-by-side colours from the colour wheel if you’re unsure what works best).
Once dry, hang your artwork out of direct sunlight and avoid twisting the canvas frame as this may crack the wax. If by chance you scratch or damage a small section of the wax, simply reheat the section with a hairdryer or heat gun.