Abstract: A method of making two-layer tablets or pellets in a twin rotor pressing machine, in which method during a normal manufacturing period powdery or particulate material is fed into die bores of a die rotor so as to form first layers, said first layers are compressed in a first step by plungers synchronously rotating with the die rotor so as to form first layer pressed articles, the two layers within the die bores are compressed in a second step by said plungers so as to obtain two-layer tablets or pellets, and said two-layer tablets or pellets are removed at a main discharge station, and in which method during an inspection period first layer pressed articles removed at an intermediate discharge station or two-layer tablets or pellets removed at said main discharge station are fed to an inspection station, characterized in that during the inspection period said first layers are compressed more than in said first step during the normal manufacturing period before samples thereof are withdrawn at said intermediat