"Convert" inventory items

We have a situation where we modify an inventory item to change it into another type of item.  For example:  We have plastic enclosures (ItemA) that we track as inventory, occasionally we send some of these out for silk-screening and this effectively makes them a different type of item (ItemB) that is tracked separately.

Is the best way to handle this to do a inventory adjustment and reduce ItemA by n and then do another inventory adjustment and increase ItemB by n?

I'm new to inventory management and just wanted to make sure I'm not missing the 'correct' way to do this.