Wash tomatoes thoroughly and put in pan. Boil briskly for 30 minutes. Run through blender. Return to pot and add about 1/4 cup salt. Bring to boil and reduce heat and simmer till they'be reduced to about 4 cups (about 45 minutes) Lightly oil a cookie sheet (not aluminum) and spread the tomatoes out. Bake at 200* for 30 minutes or until the paste is thickened up. Let cool and put into ice trays to freeze. Pop out of ice trays after frozen and put into freezer bag.