This will be done in line correct? There are two ways I can think of to handle this.
1) Sell them the whole roll. Put the roll in the system as normal and create roll labels with the number and A, B, C…. so they know what they are getting.
2) The second way is to not sell them the whole roll and in the BOM create an item number we call edge trim with a negative value. This will “Create” the edgetrim item in AX and consume the other raw materials. We do this in a secondary process where we take a full roll and cut it creating a new item number and the edgetrim. Below is the BOM for that from AX.