Before we get to that, it's important to know that hand tied hair refers to the construction of the weft, not the installation method. Both hand tied wefts and machine tied wefts can be hand sewn into a person's natural hair.
Loose hair is sewn into the weft by a machine. The hair is fed through a machine and sewn together, creating a track. Machine-tied wefts are usually thicker and a little bulkier than hand tied wefts, but are sturdier and can handle many different types of installation methods. They are packaged as one long weft and designed to be cut with minimal shedding into the desired lengths needed for the install.
Machine Tied wefts are more durable, can be installed with various methods & can be cut to custom size without shedding.
Loose hair is individually hand tied onto a hand-sewn weft by an experienced technician. This attention to detail ensures that hair is more strongly secured and does not shed, making the hair extensions last longer. They are also thinner, flatter, and more flexible than machine tied wefts, allowing the hair extensions to lay closer to the scalp and provide a more natural look and feel.
Hand Tied wefts should NOT be cut. Cutting a hand tied weft will cause the weft to unravel and shed. Hand Tied wefts are typically already packaged into smaller widths that can better fit a client's head without cutting.
Hand Tied wefts are thinner, easier to blend with natural hair and typically more comfortable to wear.