a percolator having a cylindrical basket concentric with a wand is provided with a filter paper cup having an annular bottom coextensive with the bottom of the basket and having upstanding fluted sides . the filter cups are formed by cutting and forming them into a nest of cups having an imperforate bottom , transferring the nest of cups to a frusto - conical die having a circular top commensurate with the circular bottom of the filter cups , a central die - hole , and outwardly and downwardly flaring sides corresponding to the natural outward flare of the nested cups , and punching an axial hole in said nested cups while on said die by means of a punch complementary with said die - hole .