Do tams help tighten your dreads? - Dreadlocks FAQ's
Yes, a little. Tams hold your dreads together and force them to bounce and rub against each other. This helps them lock much the same way that sleeping on them helps. I have seen some sites that recommend putting wet dreads in a tam to dry in order to help them tighten. I would advise against this. It won't take long for wet dreads to soak the tam and then you have a soppy wet tam holding soppy wet dreads. They will stay wet this way all day, or longer. This is a good way to grow mildew and get "dread rot" (really stinky dreads caused by mildew rotting inside them). If you squeeze as much water out of you dreads as possible and then use a blow dryer to dry them even more, you can put them in a tam nice dry and you'll never have to worry about tha rawt.