Now when we left our wool it had just been shorn from our sheep. It is however, raw, oily from being on the sheep, likely still somewhat dirty, of uneven grades and types and also of course contains the other two fibers in the fleece (hair and kemp) which need to be removed before it can be used. The various processes used to get wool ready for spinning (or for sale) were sometimes collectively called “dressing” and involved various methods of sorting, scouring, combing, and washing.

The first step is sorting, dividing the raw wool into grades and types based on any number of factors, including fiber length, color, texture, crimp, strength, ability to take dye and so on. Different parts of the sheep produce wool with somewhat different qualities in this regard, but there are also differences based on the sex of the sheep, their health, age, diet, and for ewes whether they have had lambs. In order to get the best results in spinning (or the best value in selling) it is necessary to separate these grades out, grouping like wool with like. Too much mixing of fiber quality can make the end-product textile patchy in color, texture and its ability to take dye (the last one being quite visible, of course) and is to be avoided. This sorting was generally done by hand.

At this point, with the wool sorted, it could be sold, or further processed. The key question at this point was if the wool was to be washed or scoured (it would be combed or carded in either case, but this decision generally has to be made at this point). Scouring removes the lanolin (an oil secreted by the sheep which effectively waterproofs their wool) and other impurities. Leaving the lanolin in the wool can help with the spinning process and also to preserve the wool, but if the wool is to be dyed before being spun (for instance, if it is to be made into colored yarn rather than dyed as a whole fabric after weaving), it must be washed (or the lanolin will prevent the dye from sticking). Scouring could also be useful for wool that was going to be transported; in some cases the lanolin and other impurities might amount for up to 40% of the total weight of the raw wool (Gleba, op. cit. 98).

Practices in this regard clearly differed. In Greece, wool seems often to have been spun unwashed and women might use an epinetron, a ceramic thigh-protector, to keep the grease of the wool roving off of their clothes. On the flip side, both Varro (Rust 2.2.18) and Columella (De Rust. 11.35) assume that wool is generally to be washed (though they are thinking of wool being sold by large estates for commercial purposes and thus may have dyeing in mind). J.S. Lee notes that in medieval England wools with longer staples (that is, that forms into longer clusters or locks of fibers) were unscoured while short staple wools (which might be used in knitting) were more likely to be scoured. Scouring might be done on a small scale in the home or on a larger scale by either producers (before sale) or by clothiers and other purchasers (before dyeing).

Pre-modern scouring generally meant bathing the wool in a solution of warm water along with some agent that would remove the lanolin and other greases and impurities. The most common scouring agent was urine, something that pre-modern communities had in abundance; the ammonia content of urine allows it to break up and wash away the greases in the wool. Alternately, in the ancient period, the soapwort was sometimes used, as soaking its leaves in water could create a form of soap. By the early modern period, potash might also be used for this purpose, but even in the 1500s, it seems that urine was the most commons scouring agent in England. The process is smelly but generally fairly simple: the wool is allowed to sit in a solution of the scouring agent (again, generally urine) and warm water. Scoured wool would need to be re-oiled after it was dried to lubricate and protect the wool; typically olive oil was used for this purpose (both during the ancient and early modern periods) although J.S. Lee notes (op. cit. 45) that in the earlier parts of the Middle Ages, butter might be used instead in parts of Europe where olive oil was difficult to obtain in quantity.

Next, the wool has to be carded or combed, to remove any unusable or imperfect fibers or dirt, along with separating the strands by length and getting any tangles out before spinning. Let’s treat combing first, as it is the older of the two methods. Wool combs (in the ancient world, these were generally made of wood, bone or horn, but combs from the medieval period onward seem to generally be made with metal teeth projecting through a wooden handle) were used in pairs with the aid of a lubricant (grease, olive oil; these days there are specialty “combing oils”). One comb, the “moving comb” would be worked through the wool while the other comb which held the wool together was kept stationary, sometimes on the comber’s knee; in some cases it would secured to a fixed post (called a “combing stock”). You can see a demonstration of the basic method here.

Carding came later, though I have found no consensus on how much later. Gleba (Textile Production, 98) suggests that carding may have been in use in Italy by the end of the Roman period, while J.S. Lee (op. cit., 45) supposes carding to have been adopted into Europe via borrowing from the Islamic cotton industries of Sicily or Spain in the late 1200s. These suggestions are, of course, not mutually exclusive but I am hesitant to render a verdict between them. In any event, by late Middle Ages, carding is also a reasonably common processing method. Hand carders are generally wider, more paddle-like wooden boards with handles and pierced through by iron teeth; the earliest carders used teasel heads in place of the iron teeth (and the word “card” here actually comes from Latin, carduus, meaning thistle, referring to the use of teasel heads). Like combs they are used in pairs, with the wool placed on one, often held on the thigh, and then the other carder is drawn over the first until the wool is ready for spinning. You can see a demonstration here, and a direct comparison of the two kinds of tools here.

Though obviously quite similar methods (albeit with different tools) the two methods produce importantly different results in a couple of different ways. Both methods will remove remaining hair or kemp along with dirt or other particles that aren’t wool. But combed fibers generally produced stronger yarns (as I understand it, this is partly because it doesn’t straighten them out so much, allowing them to better tangle together during spinning), but combing is also a bit more wasteful in material terms, as shorter fibers are discarded in the process. Consequently, once both processes were available, they might both be used (and still are by practitioners of traditional wool-working today, as the video links above show), with combing more often used for long-fibered wools and carding for short-fibered wools.

Bret Devereaux, “Collections: Clothing, How Did They Make It? Part II: Scouring in the Shire”, A Collection of Unmitigated Pedantry, 2021-03-12.