Mass. Gen. Laws ch. 255 § 31B
If any part of the amount for which goods are held under said lien remains unpaid for a period of ten days after the earliest item of said amount becomes due and payable, the lienor may sell said goods at public auction, first publishing a notice of the time and place of said sale once in each of two successive weeks in a newspaper published in the town, if any, otherwise in the county, in which said goods are situated, the last publication to be not less than five days prior to the sale and, if the residence or business address of the owner of said goods is known or can be ascertained, sending by registered mail a copy of such notice to said owner at such address at least five days before the day of sale; provided, that if said goods are readily divisible, no more thereof shall be so sold than is necessary to discharge the underlying indebtedness and cover the expenses of the sale. The proceeds of said sale shall be applied to the payment of said indebtedness and said expenses and the balance, if any, shall be paid to the owner or person entitled thereto. The remedy herein provided to enforce said lien shall be in addition to any other provided by law.
Mass. Gen. Laws ch. 255, § 31B