Bring 4 ¾ cups water and 3 ⅓ cups sugar to a boil.
Add one (1 lb.) package of Flavorland brand Marion blackberries to the syrup.
Bring to a boil again.
Thicken with three rounding ⅓ cups of red berry pie tone diluted with 1 cup water OR three rounding ⅓ cups corn starch.
Remove from the stove.
Put in one (1 lb.) package boysenberries and one (12 oz.) package frozen red raspberries.
Fold berries in gently and let cool.