I found this stuff at the 'Dollar Store' in BC Canada. It's officially called FLORAL TAPE, and It's $1 for a ribbon of 60ft (by 1/2")).
It is quite low drag, waterproof and stretches to about 70-80 feet if you pull on it. The great thing is that it's wax coated tissue paper of sorts (party ribbon stuff). Now that may sound heavy, being wax coated and all, but with technology these days, believe me its light!
It comes in dark brown (cloudy days) and white (sunny days). It is quite strong (holds up to the ground handling yet snips or breaks easily in the air), we usually twist and then tie several pieces together and go flying(no point in throwing out a snipped ribbon). At the end of the day we just roll it up and throw it into the field box for the next day....

It's called Floratape Roll by Artisanaut Craft Supplies.
WWW.ugarit.ca