An autoclave bag is a pouch tattoo artists use to store needles. The needles should not be removed from the bag until the client is seated and ready to proceed. The client may also ask to see the sterile confirmation logo on the bag. Usually the autoclave manufacturer will place a clearly visible label on the front of the bag.
In some states it is not a legal requirement to use new needles. If used needles are properly autoclaved, it is legally acceptable to reuse them, but this is not a recommended practice. New needles should be bright silver in color, not stained with ink or brownish looking. Used needles, if properly sterilized, can be perfectly safe. However, there is risk of the needles becoming dull after repeated use which can cause damage to the skin.