RSA 350-C:3 Liens.

I. Molders shall have a lien, dependent on possession, on all dies, molds, forms or patterns in their hands belonging to a customer, for the balance due them from such customer for any manufacturing or fabrication work, and in the value of all material related to such work. The molder may retain possession of the die, mold, form or pattern until the charges are paid.
II. Before enforcing such lien, notice in writing shall be given to the customer, whether delivered personally or sent by registered mail to the last-known address of the customer. This notice shall state that a lien is claimed for the damages set forth in or attached to such writing for manufacturing or fabrication work contracted or performed for the customer. This notice shall also include a demand for payment.