Combing is a method for preparing carded fibre for spinning. Combing aligns fibers in parallel before spinning to produce a smoother, stronger, and more lustrous yarn. The process of combing is accompanied by gilling, a process of evening out carded or combed top making it suitable for spinning. Combing separates out short fibres by means of a rotating ring or rectilinear row of steel pins. The fibres in the 'top' it produces have been straightened and lie parallel to each other. When combing wool, the discarded short fibres are called noils, and are ground up into shoddy.
In general, there are two main systems of preparing fibre for yarn: the worsted system and the woollen system. The worsted system is defined by the removal of short fibres by combing and top preparation by gilling. In the woollen system, short fibres are retained, and it may or may not involve combing.
Combing is divided into linear and circular combing. The Noble comb is an example of circular combing. The French comb is an example of linear combing.
The circular combs used have long metal teeth, and only barely resemble the comb used on hair. However, they are used in a similar fashion with one comb holding the fibre, which is slowly dubbed in by a brush, while the other is moved through, slowly transferring the fibre to the moving comb.
The rectilinear comb uses a circular comb mounted on a drum to comb out the fringe and remove short fibre (set by a scale so fibres less than, for example, 25 mm are removed) not held by a clamping mechanism. The row of pins known as a top comb is a very fine tooth comb, for example, 25 teeth per inch; it is inserted in cylindrical combed fringe to act as an impediment to contaminates (burr, seed etc.) flow. The top comb acts as an impediment to contamination moving into a combed sliver. On a next circular combing short finer and contaminants are removed. The circular combing without short fibres is placed on a moving belt in an overlapping motion. The circular combing and top comb insertion are repeated and combed fibres - now called tuft are overlapped.