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.