Top making describes the series of processes used to convert raw wool taken from the sheep’s back into a “top” or “combed sliver”, which can be described as an assemblage of fibers in continuous form without twist.

This conversion of greasy wool to wool top is typically done via the following mechanical processes:

1. Scouring – the washing of raw wool to remove dirt, grease and sweat salts (suint)
2. Carding - opening fibres into a thin web and removing much of the vegetable matter
3. Gilling - a three-stage operation which aligns the wool fibres
4. Combing - combing to remove short fibres, fibre entanglements (neps) and any residual vegetable matter
5. Finisher gilling - two final gilling steps to produce uniform sliver known as wool "top"

A key feature of topmaking involves engineering the blend of raw wool obtained as farm or bulk lots to ensure that the final top meets the required specifications for mean fibre diameter, fibre diameter distribution, fibre length and distribution, fibre strength as well as several other characteristics.

In addition to meeting quality specifications for top, the top maker is often required to meet specific price points.

The topmaker can be regarded as the “cook” in the wool combing industry. He takes different farm lots and blends them to meet the specifications and price restraints placed on him by the combing mill, much the same way as a cook takes flour, butter, sugar, eggs etc. to bake a cake. If the chef wants a chocolate cake he must add chocolate in the same way as the topmaker can (and probably will) add pieces or skirtings to a blend if the end product is to be used for dark suiting fabric. In another example, the topmaker will only need to use low diameter fleece wool if the top is to be used in pastel shade next-to-skin knitwear. The analogy between cook and topmaker is a very apt one.

The widespread use of objective measurement has improved the precision of topmaking by reducing appraisal errors for individual attributes, to the extent that much blend engineering  can now be carried out using computers.