Fun to use cookie cutters to cut out shapes.
See Note for instructions to make a larger pan.
4 envelopes Knox unflavored gelatin
3 (3-ounce) packages flavored Jell-O
4 c. boiling water
In large bowl, mix Knox and fruit-flavored Jell-O. Add boiling water and stir until gelatin is completely dissolved.
Pour into a 9 x 13" pan and chill until firm. Cut into squares or use cookie cutters for desired shapes.