It might not do any good. Babies are born with this palmar grasp reflex, which means their fingers will quickly snap back into place. This reflex is often present for the first month or two and is stronger and lasts longer in some babies than in others. Try your baby’s hand to check how strong the reflex is before exposing ink or clay to air or mixing plaster. If getting a good impression seems unlikely, wait another week and check again.;If your baby’s grasp reflex is very strong, you can make the impression while the baby is in a deep sleep, or can gently bend the baby’s wrist down toward their forearm and that helps to open up their hand.;