Wash and drain the plums, put them in a preserving kettle with just enough cold water to cover them, and let them boil until quite tender, then drain, but do not squeeze, or the jelly will not be clear.
Measure the juice and put it on to boil, put the same amount of sugar in shallow pans in the oven to heat, and when the juice has boiled for twenty minutes, stir in the hot sugar. When the juice boils again pour into scalded jelly glasses set in a dish of hot water.
Seal while hot.
Striped jelly is very popular at parties where refreshments a little out of the ordinary are desired.
Place a dark jelly, such as strawberry, in the bottom of a glass jar to the depth of one-half inch. Allow this to cool; it may even stand for a few weeks if necessary. Then pour on top of it a red jelly, such as currant jelly, and continue this process with as many shades as desired until the jar is full. Seal.