Back in 1991 I was in Varanasi, India for the festival of the kites. It is a festival where right across the city everyone gets up on the building roofs and flies these little tailess diamond kites on single string which are designed to fly around in circles until you pull sharply on the string and they fly straignt for a second before resuming the circular flying pattern. The trick is to wait until the kite is pointing in the desired direction of travel and pull sharply to get it to go in that direction then wait until it loop around again and pull sharply again.
The kites cost (back then) 2 rupees for a small one and 3 rupees for a larger one. You then buy your line either single or double glassed line (lines coated with ground glass) and the game is to bring your opponent on the next roofs kite down.
We tried in vain for three days before we could even get our kite to fly high enough (about 40 feet) for anyone else to cut our line. And every time we did the guys on the roof next to us promptly cut our line.

After a week we finally took down our first kite. Huge amount of skill required and the Indians are able to get their kite hunferds of metres up to the point where you can barely see their kites. Good fun! HUgely satisfying when you take someone elses kite down. Big cheers all round

I reckon these lines would be awesome on your kite at Dolls or your local fave crowded kitespot, you wouldn't have to give way to anyone and should you touch lines with someone else you will instantly bring their kites down with severed lines.
I'm ordering a set today!

Good winds,