Tapered relief: In a tapered relief the die holes gradually taper out at the ends as the pellets leave the compression area. The instances this type of die may be used are for 'spongy' materials which could include fish feeds or alfalfa. The effect of the tapered relief is that when the wear enlarges the diameter of the hole, decreasing the compression index, this is partly recovered by the length of the compression thickness increasing as the diameter increases.