5109.10 - Containing 85 percent or more by weight of wool or of fine animal hair:

This HTS category, 5109.10, encompasses yarn composed of 85 percent or more by weight of wool or fine animal hair, specifically when such yarn is prepared and presented for retail sale. This designation is critical for distinguishing it from yarns intended for industrial use or those not meeting the minimum percentage of wool or fine animal hair. The "put up for retail sale" criterion signifies that the yarn is packaged in a manner intended for direct sale to consumers, such as in skeins, balls, or hanks of specific weights or lengths suitable for hobby or craft purposes.

The primary sibling category, 5109.90 ("Other"), covers yarns meeting the wool or fine animal hair content requirement but are not specifically prepared for retail sale. This distinction often hinges on the packaging and intended end-user. For instance, large industrial spools or bulk shipments not directly marketed to the general public would fall under 5109.90.

Within this category, further subclassification exists to refine the classification based on specific characteristics. Subcategory 5109.10.20.00 addresses yarn that has been colored (dyed or printed) and precisely cut into uniform lengths not exceeding 8 cm. This meticulous preparation is a key factor for its specific tariff treatment. The remaining subcategory, "Other," would capture retail-ready wool or fine animal hair yarns that do not meet the specific criteria of being colored and cut to a uniform length of not over 8 cm.