The technique I ended up using had you run glue along the top and bottom of the hair of the entire weft where it is sewn together, cut off a small weft, thread hair (with threader) into a large, long needle, and “sew” into place by pushing the needle from the inside to the outside of the head.
I was using the sewing technique originally, but I was cutting small wefts and tying knots into them to keep them in place. It was time consuming and messy. I did not like using a rooting tool, so I never finished a doll that way (maybe I’ll try again some day). But, I did one complete Barbie head and finished a second in one day...not sure of the amount of time. But with my starting method I had already worked on this doll several different days and easily had 1/3 of her head to go.
I purchased the hair on Amazon. I live in an area where doll making/customizing/repairing must not be much of a thing, so the craft/sewing stores had nothing. I just took a chance on some inexpensive synthetic hair and hoped for the best since I’m just learning. I would probably look for a different hair for the PJ doll I want to re-root, but also wouldn’t mind this for some other Barbies. I’ve also used this hair to make a Barbie wig.
Thanks! I picked the hair up on Amazon about a year ago.