pinch braiding/ string method extensions Help!!!!!!!

Hi,I am trying to do an article on all the various types of hair extensions & have heard of a pinch braid method & a string attachment method that are supposedly safe as in no heat or glues, I cannot seem to find anyone willing to explain these methods, so Iam asking anyone if they have had it done & if so was it ok (no damage),I am most interested in these methods & if I cannot find out how they are done I will have to exclude them from my article, which I do not want to as I would like to educate on all aspects of Safe extensions, please help!!!!!!!!.Thanks,Simone.(C)