Sew-in hair extensions, also called weave or track extensions, are applied by braiding sections of the natural hair into tight cornrows and then hand-stitching wefts (strips of hair attached to a thread base) directly onto these braids using a needle and thread. The process typically takes 2-4 hours and requires professional installation, though some people do self-install.
The preparation begins with the stylist washing and sectioning your natural hair into rows, then creating cornrow braids that serve as the foundation. These braids must be tight and close to the scalp for proper tension. The hair extension wefts are then sewn onto each braid using a curved needle and thread that matches your hair color, with multiple passes ensuring the extensions stay secure.
Sew-in extensions typically last 6-8 weeks before needing maintenance, as your natural hair continues to grow underneath and the braids gradually loosen. During this time, you wash, condition, and style the extensions like natural hair, though you should avoid putting excessive tension on the roots.
The main advantages include durability, the ability to add significant volume and length, and a natural appearance when properly installed. Drawbacks include the time investment for installation and removal, potential tension on the scalp if done incorrectly or kept in too long, and the need for careful hair care to prevent matting and maintain the braids. Removal requires cutting the threads and unbraiding the cornrows, which should be done carefully to avoid damaging natural hair. The method works best for people with healthy hair and a scalp that tolerates tight braiding.