Move stock from one item to another (like conversion but different)

[AndrewBPF]

I'm setting up a fabric store which caters to quilters. We generally sell fabric by the yard and cut it from the bolt to the customer's request. I have yards set up as a custom unit and this works fine. We also sometimes have employees cut "fat quarters" (a quarter yard cut in a square rather than the long skinny way) from the bolt, and then put those pre-cut fat quarters on the shelf for customers to buy (priced per each). We can't use the "stock conversion" feature for this since once 2 fat quarters have been cut they cannot be sold as 1/2 yard again - it's no longer the same thing. How do I handle this in my inventory? Is there a way to reduce the stock of the main fabric by 1/2 yard and increase the stock of fat quarters (a different item) by 2 units? Ideally this would maintain tracking for COGS etc. Thanks!