Hi;
No You Don't! You can get sheets the thickness you need. Then Clamp them to a piece of glass( Tempered) and using a non skid ruler( Stainless) Set the strip width and draw a Polycarbonate cutter gently down the length of the sheet. That sets the line. Gently draw a Scratch Awl down that line till it separates. Do not try to break or bend it off. Just go slow and steady.
I have had to do this for some time now as the pieces in the length I needed got scarce and I found myself with the same problem. I buy my sheet from a Heating and Air supply house. They think it's funny that a Model Builder has to come to them. But we have a good laugh and they certainly take my money willingly!
One final thought. When you get a strip separated, draw it through or over a length of 320 grit to remove the sharp edge or clamp in a vice and section by section gently file it smooth!