For a knotted pearl necklace, how long does the string need to be?
A good rule of thumb is 4 x length of necklace in inches + 15 inches. That assumes you are using a doubled strand of thread instead of just one. For a 16-inch necklace, that would be 79 inches (4 x 16″ + 15″ = 79″). When using carded thread that comes with a needle pre-attached (e.g. Griffin Polyamid) you do not need to double the thread (it has already been done for you by the manufacturer).