Wool is the single most important component of a historical uniform. Here is how to read a specification and buy the right cloth.
Quick answer. Military uniform wool is specified by weight (grams per square metre), weave (broadcloth, worsted, melton), dye (fast and historically correct), finish (surface treatment). For most 18th and 19th century uniforms you want: broadcloth weave, 400 to 550 grams per square metre, vegetable dyes if possible, a slightly fuzzy surface. Modern suiting wool is lighter and wrong for period uniforms. Reenactor suppliers like Hainsworth, Woolrich and Charpentier produce specifically period correct wool.
Weight
The single most important wool specification is weight, measured in grams per square metre (gsm). For a Napoleonic infantry coat: 450 to 550 gsm. For a Victorian frock coat: 350 to 450 gsm. For a winter greatcoat: 650 to 800 gsm. For a lightweight tropical uniform: 220 to 280 gsm. Modern suiting is typically 220 to 320 gsm, which is too light for most pre 1900 uniform work. Period uniforms were made from heavy cloth that drapes and photographs completely differently from modern suiting.
Weave
The three main weaves for military wool are broadcloth, worsted and melton. Broadcloth: densely woven then lightly fulled (shrunk and compressed), surface slightly fuzzy, typical for 18th century and early 19th century uniforms. Worsted: combed yarns, smoother surface, more drape, used for later Victorian uniforms and some Napoleonic officer coats. Melton: heavily fulled, very dense, very warm, used for greatcoats and winter outerwear. Choose the weave to match the period and the specific garment.
Dye and colour
Period uniforms were dyed with vegetable and mineral dyes. Red: madder (pale brick red to crimson) or cochineal (brilliant scarlet). Blue: indigo (dark blue). Green: dye combination (yellow weld plus indigo). Black: dye combination (iron and logwood). Yellow: weld. For reenactor uniforms, you want dyes that match period examples. Modern chemical dyes can produce correct colour but often reflect light differently from vegetable dyes. For film work the dye matters particularly because of close up photography.
Finish
The surface finish of wool matters for appearance. A period correct finish is slightly fuzzy with light nap, usually brushed rather than sheared. Modern finishes include glossy worsted (too shiny for period), heavy fulling (right for melton), light fulling (right for broadcloth) and raised nap (right for some winter cloth). Avoid super shiny or super fluffy finishes: both look wrong on camera and in person. The right finish is subtle, dense and reads as period cloth without being obviously treated.
Suppliers
For UK and European reenactors, the main wool suppliers are Hainsworth (Yorkshire), Charpentier (France), Daalder (Netherlands), William Sugden (Yorkshire for military contracts) and various smaller specialist mills. For US reenactors: Woolrich, Pendleton, various Civil War era specific suppliers. All these mills produce wool specifically for military and reenactor use, often in historical weights and colours that are hard to find elsewhere. Cost per metre: 25 to 80 pounds depending on weight and quality.
What to avoid
The most common mistake in uniform cloth selection: lightweight modern suiting wool. The drape is wrong (thin and clingy), the colour reflects wrong (too bright), the surface is wrong (too smooth), the hand is wrong (too soft). Avoid wool blends (wool poly is particularly bad for period uniforms). Avoid very hot pressed finishes. Avoid any kind of waterproofing or stain treatment: historical wool is just wool. The right wool is heavier than you expect, denser than you expect, and feels substantial in the hand.
Common questions
What weight for a Napoleonic coat?
450 to 550 grams per square metre. Lighter than this will not drape correctly.
What weight for a Victorian frock coat?
350 to 450 grams per square metre. Slightly lighter than Napoleonic to reflect the Victorian preference for a slimmer silhouette.
Can I use modern suiting wool?
No. Modern suiting is too light. The drape and photography are both wrong for pre 1900 uniforms.
Where do I buy period correct wool?
Hainsworth, Charpentier, Woolrich, Daalder and other specialist mills. Also from reenactor supply houses who order from these mills.
How much wool do I need for a coat?
For a hussar dolman: 2 to 2.5 metres. For a Napoleonic coatee: 2.5 to 3 metres. For a Victorian frock coat: 3 to 3.5 metres. For a greatcoat: 4 to 5 metres. Add 0.5 metres for errors and pockets.