Mich. Comp. Laws § 429.204: Unlawful laundering of articles.

Sec. 4.

No person, firm or corporation, other than the owner or owners shall launder, wash, clean, renovate or cause to have laundered, washed, cleaned, or renovated, any towels, coats, aprons, toilet devices or other supplies used for the purpose of cleanliness and sanitation, which is so marked, named or distinguished, as aforesaid, the possession of which is claimed by lease, or rental from the owner thereof as herein provided, except by the written consent of the owner or owners thereof.