If you need to create a SKU in order to book in items on a PO you can do it on the fly via the Item Picker
From within the Item Picker, Click New
In the product type drop-down, select the product type, owner
and populate the other fields as needed (Colour, Style, Category,
Description and VAT type_
Click Create and Select
Click Use Selected Items - this will add this into the PO joblines tab for you to add the quantity details
Tip
If you need to create SKU's to represent the differing sizes of a garment - create one first, then simply change the Size field value and click Create and Select to create the new size. Rinse and repeat until the size range has been created.