Hair 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.
There are three major categories: Strand by strand extensions, weft extensions, and clip-on extensions 

Strand by strand Hair 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.

Glue/Bond based attachments: D'Vine Lengths: is a hair extension system that matches to the contour of your head. This system is very flat. The inventor claims that this system is virtually undetectable even in fine, thin hair. The bonds are flexible what makes them comfortable as you sleep. The New innovative interlocking system eliminates slipping and shedding. With these hair extensions every strand can be reused.

Glue/Bond based attachments

D'Vine Lengths: is a hair extension system that matches to the contour of your head. This system is very flat. The inventor claims that this system is virtually undetectable even in fine, thin hair. The bonds are flexible what makes them comfortable as you sleep. The New innovative interlocking system eliminates slipping and shedding. With these hair extensions every strand can be reused. 

So.Cap. USA Hair Extensions: This method introduces an innovative and advanced equipment in the field of cold fusion, 'Flat Ice'. The hair extensions are attached using the highest standard of ultra sound technology combined with a very easy and practical use of the machine. It works by transforming the electrical signal sent by the main unit into waves that soften the keratin. So.Cap. USA hair is available in 81 colors which are available in straight, wavy and curly. Each strand of hair is 100% unprocessed human hair with no silicone coat.

Donna Bella Hair Extensions: Donna Bella Milan is known amongst hair professional's world wide for its certified remy human hair. Besides trading raw human hair for both wigs and extensions, Donna Bella also manufactures their own unique line of products. The Kera-Link system is applied using a flat-tipped heat tool that fuses the extension into the client's hair. The European formulated bond comes in a flat shape that can be cut into smaller pieces making it very difficult to see.

Great Lengths Hair Extensions: This method is based on a gentle principle, 'modulating'. The attachment of the hair strand to your own hair is composed of polymer chains whose molecular structure is very similar to that of human hair. A special applicator joins the strand with your hair. Easy to install and remove by an expert. Great lengths uses the highest quality hair available.

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.

Cinderella Hair Extensions: These extensions are attached to your own hair at low temperature with a protein-moulded bond. The bonds are strong and flexible and made of protein that is not harmful for your hair. In general a high hair quality is used with these extensions

Ultratress Hair Extensions: This application method can be used on areas on the head where ordinary extension can't. A polymer bond is used for the attachment.

Mega Hair Extensions: With this method a keratin based hi-tech adhesive is used for application. Because the bonds are slightly thicker this method is not recommended if you have very thin hair.

Ultra Strands Hair Extensions: This is a bond attachment like Great Lengths and Cinderella. The bond is made of a different material but can be small and long lasting.

Racoon Hair Extensions: This technique uses a 'hot bond' method. The bonding material has been specifically designed for hair extensions and provides a balance between strength, durability and, importantly, ease of removal. The bond is kind to the hair during application and equally gentle on removal.

NON Glue/Bond based attachments

Donna Bella Hair Extensions: The I-Link system is applied using micro links. Donna Bella has two types of links that come in different sizes. Their most popular is the "non-slip" link that is threaded on the inside which secures the extension without damaging the client's 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.

Microchet Hair Extensions: One of the latest inventions in the field of hair extensions is a very gentle thread technique that is virtually undetectable. The process is quick and easy with no pulling or stress and no damage to your own hair. It is very comfortable and light, you can hardly feel it yourself. The attachment is so small that it can be applied on very thin hair and on areas of the head (temples, mid scalp, fore head) where most other systems can not. High quality human hair is used.

Invisible Strands: The extension hair is applied to a strand of your own hair using dental floss, the floss is then removed leaving an invisible strand. A sealant is applied to each extension to ensure that it lasts the duration of the process. The technician said that this method lasts from 8 months to a year. It could take 3 to 8 days to complete with 2 specialists working on your hair. The process does not cause damage to your hair. You care for your hair like normal.

Pro Hair Extensions: A gentle method of attaching synthetic hair extensions without the use glues or chemicals. The ProHair is braided into the hair using a 3 stem braid close to the root area, some of the extension fibre is wrapped around the braid and then heated with the ProStyles Heat Clamp. The ProHair shrinks around the braid locking it in place and preventing it from unravelling. Removal is easy as well, simply twist the heat seal until it fractures then the extension slides out without any damage to the clients hair. Gentle because it does not rely on tension or chemicals for application or removal. It is also suitable for all hair types European, Asian or Afro. ProStyles are the inventers of this method.

FLhair™ Xtensions strand by strand: This method utilizes a custom designed micro-cylinder shell. Small, weightless and strong each shell’s interior is coated with a Silicone compound to protect the hair from any compression stress. The outer shell is colored co-ordinate to match the hair color for truly sightless, gentle dependable connections. The uniqueness of this method is all the Remy Hair Strands come fully prepared with a shell and threader attached. It can be used for length or volume on all hair types, excluding medical hair loss. FLhair™ Xtensions Strand by Strand method makes it affordable and dependable for the stylist and client.

HairXtend Hair Extensions: Attachment is done with skilful manual application using a soft silicon pad that does not stress your hair. They supply only 100% cuticle hair.

Hairlocs Hair Extensions: This method is based on the same principle as micro-cylinder. No heat, no glue or polymer is used. The tubes are larger and have a different shape than the micro-cylinder but both are tightened to create the attachment.

Individual braiding: In this time consuming method extension hair is braided into your own hair.

Weft Hair Extensions

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

Flattracks: Flattracs is an exclusive method that only takes an hour to attach. It looks natural and costs half of what a full head of individuals would. There is no damage to the natural hair. No special products or brushes are required. The hand-tied hair is sewn on to a thin section of your natural hair. This technique was developed by Cynthia Orr.

Simplicity Hair Extensions: can be applied in less than 30 minutes. The Extensions are attached with specialized liner tape. This method can be used to add length, volume, highlights, and bangs. Simplicity Hair Extensions are 100% human hair and are sold pre-cut in 38 different colors and a variety of sizes and styles for all over attachment. They last 4-6 weeks with proper care and can be easily removed and reused.

Keraloc © Hair Extensions: involves a human hair weft. A tiny hook tool is used to pull a small but secure amount of your natural hair through the weft and then add a tight, silicone ,waterproof , heat activated seal around the keratin protein bond. This is repeated every half an inch around the weft. This way the weight of the extension is evenly distributed through your whole head Keraloc hair extension will grow out and need to be uplifted every 10 to 12 weeks or 8 weeks if your hair is fine or fragile. The hair extensions can be re–used, as long as you have looked after it will the correct shampoo/conditioner and styling products. This system has been developed and copyrighted by Hot Hedz.

Glam Hair Extensions: is a new technique which uses the finest quality of hair! Highlights include safe, fast, easy and full and flawless look not to mention a completely flat and reusable base which is easy and safe to wear and maintain. It is attached simply with a special medical grade tape and holds for 2-4 months. This method is actually a two sided tape method, where the tape sits on a polyurethane base and is placed on the client's hair just below the scalp. It is available in many different colors and textures and special orders are made per request.

Bonded Hair Extensions: The weft is applied with adhesive to your hair or to your skin depending on salon and stylist. For some people it will last for many weeks and for others it loosens up after the first shampoo. This method is faster and therefore less expensive than strand by strand extensions.

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. 

Clip-In Hair Extensions

As the name already revealed, you can clip these extensions into your own hair whenever you want it and take it out at night before you go to sleep.

Donna Bella Milan Clip-In Hair Extensions: Donna Bella Milan is known amongst hair professional's world wide for its certified remy human hair. The clip-in line comes in both natural and fantasy colors. Clip-in hair is thought to be the easiest of all systems to apply and remove. Clips come in all sizes and lengths used for both highlights and full heads.

Before having your hair extensions done, ask your stylist
about the method and the hair that will be used.