Ask an adult to iron the t-shirt carefully. Slip a protective piece of cardboard inside the t-shirt so that the paint does not soak through to the back.

Using your fingers, paint the shape of a silver fish in the centre of the t-shirt.

Have an adult cut a potato into quarters to make a half-oval shape.

Use this potato as a stamp to paint the waves around your fish. Paint the flat part of the potato blue using your brush.

Start with the waves around the fish then move down to the bottom of the t-shirt, placing them in staggered rows.

Finish with the waves at the top of the t-shirt.

Let it dry completely and ask an adult to fix the paint using an iron.