Spinning wool into yarn to be woven into cloth predates 10,000 BC. Exportation of wool products began as early as 55 BC in Great Britain. Today, the wool industry circumnavigates the globe; the durable and water resistant properties of wool make it a very popular textile fibre. The wool refinement process begins with sheep (or another wooly animal such as an alpaca). The sheep is sheered so the fleece is obtained in one piece. Then, the wool undergoes preliminary y sorting to remove inferior sections. After sorting by length and width of the fibres, the wool is scoured.

Scouring removes grease, oils, and debris caught in the wool fibres. This step is important as improperly cleaned wool can lead to a greasy product or weakened wool fibres. While it is important to remove most of the grease from the wool, complete removal can lead to the inability of the wool to be stretched and spun. To keep the fibres hydrated, lubricants are often added to the scouring baths to prevent the wool from becoming stripped. The pH of the scouring bath is a critical parameter. If the pH of the bath is not properly balanced (depending on the type of bath), the fibres may fray and become brittle.

More traditional scouring treatments include a warm alkaline water wash at pH 10-11, organic solvent washes (i.e. perchloroethane) if the wool is particularly greasy, and a final treatment with water, isopropanol and hexane after the alkaline water wash. An alternative acidic scouring treatment is gaining popularity due to the speed of the wash. The acidic wash consists of a sulphate scouring solute at 150°C. During the wash, cottonseed oil acids may be added to lubricate the wool. The acid baths are usually maintained between pH 4 and 6. Maintaining the bath in this range keeps the wool in a neutral isoelectric point. This helps sustain the integrity of the wool fibres.

The main bath is usually followed by rinses in clean water to remove traces of the scouring solution. The pH is measured after scouring by performing an aqueous extract on the wool itself. Testing the pH of the wool is important as it can affect how dyes adhere to the fibers. If the pH of the wool is known, then the dye baths can be adjusted accordingly. This saves dyers time and money.

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