Today we'll be demonstrating how to drill a hole into a pearl that'll fit to create a front back earring back.  So when drilling a pearl it's important to gradually increase the hole size in order to minimize chafing or chipping the pearl on the edges of the hole. Most pearls are drilled with a standard 0.8 millimeter starter hole.  To begin use at 1.1 millimeter drill bit and drill the pearl making the starter hole a little wider.  To ensure the drill doesn't go through the entire pearl make sure your high-speed drill is equipped with an auto stopping function.  Note you can use either a standard pearl press or a micro motor flex shaft you have in your shop and achieve the same results with either.  Once the first drill is complete replace with a 2.5 millimeter bit and drill in the same spot to continue gradually enlarging the hole in the pearl.  So after checking the progress ensure your quality. move on to the three-point millimeter bit.  This will create a hole big enough to fit the back into the pearl.  Depending on the size of the back you're looking to insert you may need to go to a three-and-a-half millimeter bit make the hole little bit larger and allow room for the adhesive.  Once your 3 millimeter hole is made make sure there isn't too much cracking on the edges of the pearl. A little cracking is ok because the diameter of the earring back is a little larger than the drilled hole so it will cover the small amount.  Test fit the back to the pearl and if it's flush glue it to the pearl.