Most evacuable pellet dies operate in the same way, by pressing the analytical sample between two polished pellets of steel or tungsten carbide. The simplest way of loading the die is to assemble the die barrel and die base; insert the lower polished pellet, polished side up, into the bore; pour the sample into the bore, level it, and add the upper polished pellet, polished side down; then insert the plunger, and place the assembled die in the press. This approach works well if the sample coheres well under pressure and is neither abrasive nor adhesive; once the sample disc is pressed, it should be fairly easy to remove it from the die, either by hand or with the use of the knockout ring supplied with each SPEX SamplePrep die.

When the sample does not hold together well after pressing, or sticks to the die or scratches it, there are various pelletizing aids available. These include Spec-Caps, PrepAid binders, Sleeve-and-Plunger sets, and various anti-sticking agents. Each has its proper application and technique, detailed below.