A lock of curly hair
  1. Remove or salvage one hair.
  2. Tape one end to a butter knife, pencil or a ruler.
  3. To the other end of the hair, tape a thin plastic baggie.
  4. Over a sink, hold the hair and butter knife in one hand and have a bowl of water and tablespoon ready.
  5. Start filling the plastic bag, 1 tablespoon at a time. Count how many tablespoons you can add before the hair breaks. 6½ to 6¾ tablespoons is 100 grams (depending on the weight of tape and bag).
  6. Try hairs from different parts of your scalp. Notice where the hair breaks. The weight of the bag will make it likely to break near where the bag is taped, but weak areas are also likely places for breakage. Each tablespoon is about 15 grams.