Mass. Gen. Laws ch. 94 § 285
It shall be unlawful to keep for the purpose of sale, offer or expose for sale, or sell any sewing, basting, mending, darning, crochet, tatting, hand-knitting or embroidery thread, put up or packaged in advance of sale in or on any form of unit, for either wholesale or retail sale, unless such unit be definitely, plainly, and conspicuously marked to show its net measure in terms of yards or its net weight in terms of avoirdupois pounds or ounces.
Any unit of such thread, the net weight of which is less than two ounces avoirdupois, shall be marked to show its net measure in terms of yards as unwound from the ball or from the spool or other holder. Ready-wound bobbins which are not sold separately shall not be required to be individually marked, but the package containing such bobbins shall be marked to show the number of bobbins contained therein and the net weight or measure of the thread on each bobbin. Any retail unit of thread, sold only for household use, consisting of a package containing two or more similar individual units, which are not sold separately, shall be marked to show the number of individual units in the package and the net weight or measure of the thread in each individual unit, but this proviso shall not apply where the individual units are separately marked.
Mass. Gen. Laws ch. 94, § 285