Instead of having a separate length of cord why not make them all 1ft? The item would then be called "ft of Cord" and the length would be in the quantity. Each recipe would make 15 pieces. This would eliminate quite a bit of micromanagement and be easier to program. It would also cut down on item limits as each grade of cord would be 1 item no matter how many feet you have. Same could be done for rope.
Just a suggestion.
- Shane