Different hair knotting techniques are used to knot hair into the base membrane, providing different performance and aesthetic results. Hair knotting is generally performed in Asia where costs are significantly cheaper for what is a labour intensive hand skill. The quality of the wigmakers workmanship will have a great impact on the finished look.
Single hair, single knots are considered the best method of knotting producing a tiny knot for each individual hand-tied hair. Two or three individual hairs can be single knotted at one time speeding up the process to the detrimental of creating a larger knot with less aesthetically pleasing finish.
Double knots literally involve knotting hair twice to produce a double knot which provides a stronger, more robust knot. The resultant knots are however even more visible under close inspection. This is a particular problem when trying to create a natural hairline and for this reason most front hair lines should be single hair, single knotted on a flesh tone lace material.
The term hair injection refers to the method of inserting a series of hairs through a layer of polyurethane before coating the underside of the base with a single layer of liquid form polyurethane. Upon setting (or curing) the inserted hairs remain trapped between the two transparent layers.
Hair injection is a relatively new method of hair attachment, becoming increasingly popular due to its natural appearance, free of knots.