First, you must create the unit of measure from the Unit of Measures page. This is necessary to link the unit of measure to the item. Additionally, ensure that the Unit of Measure [textile, for example] setting in the Warehouse section is activated.
Go to the Warehouse module
Select the Stock Item page
Click New
Select the Classifications
Enter the Item description
Select Has multiple UOM then choose the unit of measure chain
If desired, select the default unit of measure (i.e., the unit of measure suggested by the system in documents) from the options provided.
Click Save