Preparations
This idea is a great example of how fabric can be printed with colour in a creative way.
As a general rule for colouring textiles, it is essential to wash the fabric thoroughly with cold water without fabric softener beforehand. Fabric paint will only bond with the textile fibres if they are free of finishes.
Things to know about finishes
Most new textiles are finished by the manufacturer to give them a nice smooth and ironed look. If there is still some finish left in the fabric, the applied fabric paint will wash out and possibly discolour the fabricthe next time it is washed.