Amazon sells this if you want it in narrower widths, like 24".
What about checking with a UPS Store? They do on site packing and may have something you can use for lots less than a whole roll would cost.
Just an idea.
Also perhaps a local factory shipping department, or maybe when they unwrap furniture or appliances in retail stores.
Someone on here was offering smaller sheets that PC's came wrapped in.
You can tell that i am big into recycling.