After the poor quality Tahitian pearls are weeded out, the processor can begin the drilling process. There are two different drilling types, full-drilling and half-drilling. Full drilling is a hole that goes all the way through a cultured pearl. This type of drilling is used for pearl necklaces , where the string must pass completely through the pearl. This drilling is extremely delicate work, as the pearl is drilled using two drill bits from each side. This is because drilling with one longer drill bit would risk damaging the nacre when it comes out the other side. One slip and the pearl can be completely destroyed. Half-drilled pearls are more used for earrings, rings pendants, tie tacks, brooches, and other types of similar pearl jewelry. This type of hole only goes through only half of the pearl.
Other pearls with a single blemish on one side can but cut and then half-drilled in order to make them useful. For instance, for a pearl ring, the pearl may have had a blemish on the side of the pearl that is attached to the ring. Instead of discarding this pearl, the blemish can be cut off the pearl, and then the half-drilled hole can be drilled on the flat side of the pearl. The pearl is attached on the flat side to the ring and the result is a beautiful piece of pearl jewelry.