Machine weft extensions are a collection of hair sewn together by a machine. The wefts themselves are thicker and weigh a bit more. Machine wefts can be cut because of how they are made-- making them more durable and sturdier. Machine weft hair extensions require no tape, glue or heat for application. This is one continuous weft of hair that can be cut into smaller pieces to be customized for various head shapes. The machine weft is slightly larger than the hand-tied weft. If you decide to cut the weft to fit your needs, you must add some hair glue to the edges to prevent the thread from unraveling and shedding.