To save time, you can thread all of your size 12 needles at once and have them dangling off of the spool until ready for the next use. When you need the next needle, just separate the closest needle to the thread tip from the others keeping the others at the spool. Pull out the amount of thread you want with the one needle in that section. Now you only have to worry about putting the fray check on once for all of your needles.