extensions come in many different types. There are differences in the way hair extensions are prepared, in the technique used to attach it to your own hair, and in what kind of hair is used. Some systems only differ from materials that are used or just from name. With many techniques some kind of glue or bond is used for attachment, these methods involve coating your own hair with a chemical or foreign substance. Some glues can be harmful for your hair or skin, others are safe. Ask your stylist what type of glue will be used. There are many good salons that do not use a name brand extension technique. Hair extensions will not last forever, sometimes because the attachment breaks but mostly because the growth of your own hair. Extensions connected to your hair will get more lose as your hair grows (approximately 0.4" per month). Depending on how fast your hair grows and how well you take care of your extensions they have to be removed or retightened when they get too loose. Some systems last longer then others but in general we can say anywhere between 2 and 6 months. With some hair extensions it is possible to reuse the hair what can save you some money, this also depends on the hair quality and how well you take care of it.
Hair Extensions are not for everyone. When the hair is very thin and weak a lace wig could be a better solution.
There are three major categories: Strand by strand extensions, weft extensions, and clip-on extensions.
With this extension technique small strands of extension hair are attached one by one to small sections of your own hair by either weaving in, gluing, heat fusing, clamping with metal tubes or using waxes and polymers.
Invisible Hair extensions: The Extension is a skin replica. An air tight, water tight seal is created allowing 5-8 weeks of attachment. "Skin" base is adhered directly to your scalp by the use of an medical grade adhesive. Your hair will continue to grow out while the grafted hair addition remains attached to your scalp. It can be re-used and brushed in any direction. This method can be used if you have "baby fine" hair.
Micro-cylinder hair extensions: This gentle attachment method does not involve glues, heat, or chemicals. Tiny tubes (micro-cylinders) are used to attach the strands with a special technique to your own hair. Easy to install and easy to remove by an expert. Applied in the correct way this is a strong and safe method that will not damage your own hair. This method can also be used for weft extensions. The cylinders come in different sizes and colors but also in different qualities. This method can be used with the highest hair quality and with hair of a lesser quality, it depends on the salon.
A weft is a track of several inches long on which the hair is already attached (a curtain of hair attached together at the top and free flowing at the bottom). A weft can be made by a machine or by hand. Handmade wefts are better, they are custom made to suit your head and match your hair. The extensions are then applied by using one row (track) at the time instead of strand by strand.
Braided hair extensions: First a braid is created of your own hair and than the weft is sewn onto the braid. The number of tracks depends on what you want.
Weaved hair extensions: This is done by weaving your own hair around a number of threads. This way a track is created. The weft is sewn onto this track.
Braiding and weaving give more tension to your hair and skin because it is tight and therefore will pull more. The extensions stylist should braid the tracks firmly but comfortably, it should not hurt. Some clients complain about being uncomfortable and having headaches using these systems, others have no complains at all.