| Off-drilling is something very common in drops and circles. I am sure the same problem relates to keishi. Every pearl has a very specific drill point if it is going in a strand. It can be difficult to find, and if the right point is not chosen the pearls may "wobble" on the strand.
If you are buying finished strands by the hank and you are finding this "wobble", you need to speak with your supplier. Even the most experienced driller will make a few mistakes, but these pearls should be sold off as "scrap", not put into a necklace. If they are in a strand, it is simply an attempt to save money.
There is another common problem as well - double drilling. This is most common with lower grade, off round freshwater strands. Using a two-sided drill, if one bit slips and veers at an angle, the tips will never connect, and you will be left with two holes on one side, and one to two holes on the other.
If you are seeing something that looks like wear near the drill hole, I doubt it is the knotting. I would surmise it is more likely due to a single sided drill. It is much easier to drill solely from one side with a standard Japanese single sided drill, but many pearls will be damaged in the process. When the bit exits the pearl from opposite the entry point, it often breaks off a ring of nacre around the hole. Not every time, but often. It is not always noticable, and can probably be mistake as wear. |