Me. Rev. Stat. tit. 10, § 3551

A person who performs labor in a tannery where leather of any kind is manufactured completely or partially, whether that labor is performed directly on the hides and skins or in any capacity in or about the establishment, has a lien for that person's wages on all leather so manufactured in the tannery for labor performed by that person or that person's co-laborers, which continues for 30 days after the leather is made and manufactured, and until the leather is shipped on board a vessel or taken in a car, and may be enforced by attachment within that time.