I have an inventory item, that I need to split into 3 inventory items. 

Currently Engraved plates (individually counted), I need to "transfer" these plates from individuals to pairs within the following categories

12' pair of number plates

16' pair of number plates

20' pair of number plates

I create the 3 new inventory items, do I do a transfer to move the items from engraved plates to the new inventory item?

Example

Currently

Engraved Plates = 50 (each)

Need to move to

12' = 5 (pairs)

16' = 10 (pairs)

20' = 10 (pairs)

and have engraved plates 0 out...

Any help/guidance would be appreciated... thank you!