We require two tablespoons of milk to create your breastmilk stone. However, we can and do work with low-supply mothers, and in these circumstances, we can work with one tablespoon of your milk. When you place your order, we send you a labeled, leak-proof storage bag for your breast milk. We include instructions and we include a prepaid return envelope so that return shipping is free. You just add your milk and drop the envelope in the mailbox.