Here is what you will need to make the mixture:
2/3 cup of water
2/3 cup of flour
2/3 cup of salt
Washable tempera paint
Squeeze bottles (you can find these at an all in one store, or a craft store too).
In a mixing bowl, whisk together the water, flour and salt. Divide the dough (onced mixed) into different bowls so that if you want more than one color, each bowl will be a different color. Drop a few drops of tempera paint into each bowl. Mix and then pour/spoon the mixture into the squeeze bottle.
To make your designs, you can squeeze the bottles onto the paper (the heavier the paper the better), mixing and forming. When you are done with the design, be sure have the paper lieing flat on the table for drying.