One fruit at a time put the fruit in a food processor and process until smooth. Pour the fruit in a bowl and put it aside.
1 slice watermelon, 1/2 cup pineapple, 1 peach
Rinse out the food processor in between and repeat with the remaining fruits.
Layer peach, watermelon and pineapple into the popsicle molds, freezing slightly after each to set the layers. Since the pineapple has the thickest consistency it works best as the last layer, otherwise it tends to stick to the sides of the molds, and then the layers don't look as crisp. For my molds I used about 2 T of fruit puree for each layer.