There are two types of wefts: Machine-Weft and Hand-tied.

Hand-tied wefts are tufts of hair sewn or tied together meticulously by hand using a strong piece of weaving thread. If they’re done properly, hand-tied wefts can actually last a very long time. However, since they’re harder to make and they take longer time to complete, they usually cost a bit more. Another thing that’s good with hand-tied wefts is that they’re not very bulky or noticeable when you put them on. They’re built to be thin so they’ll blend in nicely with the hair that you already have. They stick closely to your scalp, making them look quite natural. If you run your fingers through your hair, you may not even notice the track... That's a beautiful thing. However, special care should be taken for hand-tied wefts especially if you’re going to cut the track. Instead of cutting the track, just turn the track around to the next row and keep sewing. When you reach the end you can cut the track, just be sure it’s sealed with a good fabric or nail glue. Hand-tied wefts will unravel and shed when cut from the top, make sure your stylist probably knows this so it won’t be much of a problem. Hand-tied wefts are also quite effective since they don’t shed much when they’re put on, unlike machine wefts.

Machine wefts are sewn together using a sewing machine. The quality of the hair and the track are equally the same with both hand-tied and machine wefts. Machine wefts are slightly thicker compared to hand-tied wefts, but a bulge is rarely noticeable. A lot of people prefer machine wefts because the tracks can be cut during installation, making it a bit more flexible. A good stylist can manage to make machine wefts look very natural regardless of how thick the track is. Machine wefts are easy to manipulate, and you don’t have to be careful when cutting them. You can even cut them from the top. This makes them a good choice giving you less margin for error during a hair installation.

All in all, your choice should depend on what’s convenient for you and also your stylist. Weigh your options properly before you make a choice.

Weaving in hair wefts is one way to add extensions to your hair. One of the greatest benefits of a sewn-in weft is that there is no glue application, making the wefts easier to maintain and remove.
1. Wash and condition the hair thoroughly. After washing, blow dry the hair so that it is straight with no styling products (do not grease or saturate the hair with any other oils).
2. Depending on the style of the extensions, part the hair according to a specified pattern. For example, if you are doing a full head, part the hair from crown to crown; if partial extensions are used, part the hair straight across from the base of the neckline to the crown.
3. Cornrow each parted section from left to right---or in the case of a full head of extensions, cornrow the hair around the head in a circular pattern. Be sure that the braids are tight enough to hold the extensions. The style will not last with loose braiding.
4. Measure the wefts and cut them to fit the cornrow. For thicker and fuller extensions (and also depending on the quality of the hair), the hair should be doubled and in some cases tripled to increase fullness. Also in this step, you must cut and measure the thread and hook it to the needle.
5. Sew each line of weft to the cornrow by weaving the needle and thread through the thick lining of the extension as well as through the individual cornrow. This process connects the wefts to the cornrows. Be sure to pull the thread all the way through for maximum hold.
6. After sewing the extensions to each cornrow, tie a small knot in the thread---leaving a tiny bit hanging from the extension. This is done so that the extensions can be removed easily.
7. Style the extensions and/or remaining hair. Add moisture to the scalp if desired

1. Create a part in the hair where the extension will be added. It is easier to apply hair extension with glue by starting with hair closest to the back of the neck and working up to the top of the head.
2. Measure the amount of hair needed for the area. When applying hair extensions with glue, the right amount of hair makes the difference between having too much or too little hair. The best way to measure the right amount is to take the hair track and place in the area where hair was parted.
3. Cut hair track and place on a flat, clean surface. Before applying hair extension with glue, make sure no hair is on top portion of the track.
4. Apply thin line of hair bonding glue on top of hair track. If too much glue is spread on the hair weft, it will be clumpy and hard to remove. Hair wefts will not stick or fall out if not enough glue is added.
5. Pick up the hair weft and carefully place track in head. Hair wefts with glue should be placed close to the scalp but not on the scalp. The best area of the head to apply wefts is the hair right below the scalp.
6. Repeat previous steps until hair wefts with glue create the desired body.
7. Brush hair wefts applied with glue and cut into desired style.