The best kind of hair for halo extensions is definitely remy hair. Remy hair is human hair that is manufactured by making sure that the cuticle of the hair runs in the same direction. It is also minimally processed. Remy hair is the best quality next to virgin hair. The difference between the two is that virgin hair has only one donor and has never been colored or chemically processed and remy hair has only a few donors and is minimally processed. Non-remy hair is best avoided because manufacturers tend to shave the cuticle and tips off of the hair to mask the fact that the hair does not run in the same direction. Non-remy hair may also feel soft and silky when you first buy it because manufacturers use a silicone coating to hide the imperfections. Once that coating has worn off, which is usually after a few washes, hair looks frizzy, dull, and lifeless. This is something you won't need to worry about when buying remy hair. Although remy hair is a bit pricier, it is an investment and will last much longer than non-remy. Another great thing about remy hair is that since the cuticle of the hair all runs in the same direction, shedding, matting, and tangling is greatly minimized.
As you can see, remy hair is the best choice when it comes to halo extensions, or for any extensions at all. Just be sure to be gentle with it and treat it as you would your own hair. The better care you take of it, the longer it will last.