Pinchbraid extensions were invented in the 1980s. They are individual locks of hair tied into the native hair with a durable upholstery thread.
Tape-in hair extensions last from four to eight weeks and the hair can be gently combed and washed while wearing the extensions. In addition, the extensions need to be treated with specialized shampoos, conditioners and styling products to keep them in top condition. The extensions can be easily taken off by applying glue remover and can be easily installed by using liquid adhesive or glue tape.
Clip-in weaves, also known as clip-in hair extensions, can be integrated into natural hair to add length and volume. Clip in hair extensions can be purchased for $50 – $1000, depending on the desired quality. The clip in hair extensions most commonly come in as a long strand of one contoured piece that can be cut into multiple layers for creating separate layers on a user’s head. When the hair is purchased from a beauty supply store or a specialized online brand, it comes with clips, which are sewn into the hair. It is also possible to buy the hair (in bundles) and the clips separately, the clips can then be sewn on easily by the purchaser or by a stylist. Once the clips are sewn in, the user clips in the hair herself  or can visit a stylist, to help create a look that is natural.
This technique is the least permanent and lacks the disadvantages such as traction alopecia associated with glue extensions. The hair weft has small toupée clips sewn onto them. Usually a set of clip-in extensions averages eight strips of human hair in varying widths from two inches to eight inches. Starting at the nape of the neck, the hair is sectioned neatly, then the weft is placed onto this section with the clips open and facing the scalp. Each clip is snapped into place. It can be helpful to lightly backcomb each section for a more secure grip. This is repeated until each clip-in weft is in place. Clip-ins can be worn for an entire day; however, some people take them off to sleep.
Bonding is a method of weaving that lasts for a shorter period of time in comparison to sew-in weaving. It involves the application of hair glue to a section of wefted hair then onto a person’s natural hair; special hair adhesives are used in bonding to prevent damage to one’s natural hair. This technique is commonly used and does not cause damage to the hair unless taken out without proper directions from a professional. It is advised that weave bonding be installed for up to 3 weeks because the glue begins to loosen up and lessens the attractiveness of the hair. There are 2 types of bonding methods: soft bond and hard bond. Soft bond is flexible and comfortable to wear and is made using latex/acrylic based adhesives. Hard bond is the industry term for bonding treatments whose adhesive contains cyanoacrylate, or super glue. Hard bond adhesives last longer than soft bond adhesives because it is not water based and therefore less susceptible to deterioration. Nonetheless, the hard bond adhesives are not as comfortable as the soft bond adhesive because they are rigid. These bond attachments generally last 4–6 weeks before a maintenance appointment is necessary.
Fusion method involves a machine similar to a hot glue gun used to attach human hair extensions to individual strands of one’s natural hair of about 1/8 to 1/4 inch squared sections for a truly authentic look. Another option for fusion attachments is using hair which is pre-tipped with a keratin adhesive. A heat clamp is then used to melt the adhesive to attach the extension hair to the natural hair. Fusion weave allows washing hair frequently and the use of regular hair products such as hair gels. This technique is very time consuming taking 3 or more hours. They need re-positioning every 2–3 months as the natural hair grows. Due to various chemicals in the glue, which may cause hair loss and scalp irritation, combined with heat, this method is more damaging to natural hair.
Micro ring (also known as micro-bead or micro loop) hair extensions use small metal rings or beads (usually aluminum) and can sometimes be lined with silicone to attach the extension hair. They are fixed to small sections of natural hair and tightened using a special tool that clamps the bead around the natural hair.
The micro-beads are designed to be small enough so that they are not visible in normal use. They need re-positioning every two to three months as the natural hair grows and the micro-beads move away from the scalp.
As they do not use heat or adhesives, these hair extensions should cause less damage than some types of extensions, if placed correctly and properly taken care of. Today, there are many sizes available for micro rings/beads from about 1.5–5.5 mm (0.059–0.217 in). The sizing makes a difference on the weight of the extensions, the feel, and the visibility. Some micro-beads are so tiny that they mimic a non surgical hair transplant. The stylist installing the extensions should determine what size micro rings/beads are best for the client’s hair length and texture, prior to installation on the head.
The glued netting process near completion
Netting is a technique which involves braiding natural tresses under a thin, breathable net that serves as a flat surface onto which stylists can weave extensions. This method requires the use of hair net or cap to be placed over the person’s hair that has been braided. Netting provides more flexibility than track placement because the stylist is not limited to sewing extensions to a braid. With netting there is the option of sewing the hair wefts onto the net or gluing. This technique is not as time-consuming when compared to the other hair techniques because it takes about 2–4 hours to complete.
Section of a lace front used to close a weave (also called a lace or closure)
The most recent development in weave extensions are lace fronts, which are made from a nylon mesh material formed into a cap that is then hand-ventilated by knotting single strands of hair into the tiny openings of the cap, giving the hair a more natural and authentic continuity than typical extensions. It has few variations including straight, wavy and curly. Furthermore, the extension units can be woven in or attached to a person’s hairline with special adhesives. To ensure a proper fit, head measurements are taken into account with this type of weave. A lace frontal is best placed by a professional since more advanced weaving and hair extensions are used. This method is commonly used because it makes it possible to have access to a certain part of their scalp.
Tracking involves the braiding of a person’s natural hair. This is one of the most commonly used methods as it is quite fast and lasts considerably longer than other techniques. However, it does not allow for regular hair maintenance. In order to prevent the hair from being bumpy or uneven, the hair is sewn horizontally or vertically across the head from one side to the other starting from the bottom. The braided hair is then sewn down and the hair weft extensions are sewn onto the braids. A weave can consist of a few tracks, or the whole head can be braided for a full head weave. With a full head weave, the braids are sewn down or covered with a net. Extensions are then sewn to the braids. The number of tracks used depends on the desired look.