Well, I was adding nylon loom to a few other wires on my GS and it is a pain to cut .. so stumbled on a hack : humble Ikea bag clip does wonderful job to hold the loom open and cut in a straight line using ordinary scissors 
...
https://www.ikea.com/us/en/p/bevara-sealing-clip-mixed-colors-50339169/
...https://www.ikea.com/us/en/p/bevara-sealing-clip-mixed-colors-50339169/