Manja (kite)

Manja (or manjha) is the abrasive string used for fighter kites in Afghanistan, Bangladesh, India, Nepal and Pakistan. It is gummed, coloured and coated with powdered glass. In Brazil, the mix of glue and powdered glass is called "cerol". In Chile, the sharp thread is called "hilo curado" (fixed or drunk, thread).

Kites are flown throughout the year and during special kite flying festivals in the region. Two fighters will entangle the glass powder coated manja while flying their kites in the sky and try to cut off the string of each other's kites by pulling it.

The winner's kite keeps flying while the loser's kite gets cut and drifts away with the wind. Children and/or adults run after a cut kite and try to capture it when it falls to the ground, a practice called kite running.

Traditional recipes use rice gluten, tree gums and similar natural ingredients, and the exact recipe is often a closely guarded secret of the individual maker. By contrast this is a modern recipe used by some in Tamil Nadu:

Ingredients

The water is boiled with the addition of vajram, to which is added a paste of maida and finely powdered glass pieces to make a thick colloidal solution and the abrasives are added. The colouring is added, while stirring is continued to make a thick paste without the sedimentation of the glass and abrasives.

Manja can be dangerous to birds and to humans.

In Chile the use of "hilo curado" is forbidden by law, only exceptions are allowed for professional kite flyers in secured locations, only with threads for competition, coated with silicon powder. "Chilean government ban manja lines". 

Many people also get seriously injured and lose their lives when they fall off rooftops when flying and fighting kites and handling the manja reels and vigorously pulling or releasing it during battle of the kites. In the Indian subcontinent kites are generally flown and fought from the rooftops of houses.

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Wikipedia