How to manage variable size items while doing production Order confirmation

Hi All

     There is a Polythene Roll of 1000 Kg which is having a width of 895mm, now there is a process of slitting that Roll in to 4 Nos equally for 220mm. After cutting Process, Also, Client wants to weigh that and enter the Kg unit for each slitted roll.  The Problem here is, All the Slitted Rolls are considered as FERT Material and the sales order quantity will be in Kgs,

Experts, please guide me that how I can manage this situation?

Regards

S. Valmiki Sanjeev.