What you need:
Watercolor paper, masking tape, many different colors of watercolor, about 6 different colours of your choice (I used vridian, alizarian crimson, vermilion, ultramarine, burnt sienna, ivory black and white), a little sponge, some water.
How to do it:
First you have to put the tape in the geometric way as you can see in the picture above.
You star to painting using your sponge, mixing water and paint but do not put to much water.
When you finish to paint all paper, let the painting dry completely before taking off the masking paper.
To finish, I used black and white to paint the stripes, always using my sponge.