brotherton-erpnext/erpnext/docs/user/manual/en/stock/item/item-variants.md

A Item Variant is a version of a Item, such as differing sizes or differing colours (like a blue t-shirt in size small rather then just a t-shirt). Without Item variants, you would have to treat the small, medium and large versions of a t-shirt as three separate Items; Item variants let you treat the small, medium and large versions of a t-shirt as variations of the one Item 't-shirt'.

To use Item Variants in ERPNext, create an Item and check 'Has Variants'.

• The Item shall then be referred to as a so called 'Template'. Such a Template is not identical to a regular 'Item' any longer. For example it (the Template) can not be used directly in any Transactions (Sales Order, Delivery Note, Purchase Invoice) itself. Only the Variants of an Item (blue t-shirt in size small) can be practically used in such. Therefore it would be ideal to decide whether an item 'Has Variants' or not directly when creating it.

On selecting 'Has Variants' a table shall appear. Specify the variant attributes for the Item in the table. In case the attribute has Numeric Values, you can specify the range and increment values here.

Note: You cannot make Transactions against a 'Template'

To create 'Item Variants' against a 'Template' select 'Make Variants'

To learn more about setting Attributes Master check Item Attributes