Q. I was told that black threads are black because they were dyed incorrectly and then are re-dyed as black to help re-use what would normally be wasted thread. Does this twice dying method make it break easier? Is black thread weaker than other colors?
A. Not all black threads are over-dyed. I am not sure which companies sell black thread which has been over-dyed. Over-dyeing is the process of subjecting a thread to multiple dyeing treatments, if the thread was mis-dyed and ends up an incorrect color the first time. Some companies put all the mis-dyed colors in a reject bin and over-dye them black. The excess amount of dye in these over-dyed threads can cause the fibers to weaken. (note: Superior Threads are never over-dyed.)