Materials
Urushi (Lacquer)
Samurai armor is famous for its polished and smooth “lacquered” finishes found on all of its metal and leather surfaces. The material used to create these finishes is quite a bit different than what is traditionally called lacquer in the west. Despite the term “lacquer” being the commonly used term, the substance, urushi, is not a lacquer at all. Nor is it similar to just about any other type of surface coating commonly associated with how things are painted. Urushi can be thought of as more of an incredibly strong organic glue whose desirable properties can be enhanced through additives and a unique curing process. It is the same material and process that is used in traditional Japanese lacquerware.
As described in the video, urushi is the sap from the Asian Lacquer Tree whose scientific name, Toxicodendron vernicifluum, gives away another of its famous properties – its quite toxic! Most people have some degree of allergic reaction in the form of a rash anywhere the urushi comes in contact with the skin. The severity ranges from none/mild to severe lasting weeks, and is generally the same person to person as their reaction to poison ivy, sumac, or oak. The chemical for the reaction, urushiol, is also what gives it the other desirable properties; namely hardness and adhesion.
The process to achieve the exact qualities desired by any urushi coating is an incredibly advanced topic that is way beyond the scope of this website. But the key elements to understand are that urushi must cure in a controlled high humidity chamber called a furo. This curing process can take anywhere from a day to many weeks depending on the mixture and desired effect. Once again, depending on which step is taking place, this one layer is then sanded to remove imperfections and then the next is applied and the curing process is repeated. This gets replicated over and over again over months to finally achieve the deep, richly colored, and protective surface.
An excellent resource to learn from is from the fountain pen hobby. It is common to use urushi to coat and protect the wooden portions of the pens. Here are two channels to get started with:
Odoshi
The term “odoshi” did not originally refer to silk lacing as leather was the primary material for lacing armor prior to the 13th century. Despite leather being superior in terms of durability, new techniques in silk braid production and ease of use during construction saw a rapid increase of adoption. It was after this period that odoshi became synonymous with silk.
Taken as a whole, the color of odoshi used in any given armor had no meaning associated with any sort of moralistic value or represented virtues the samurai might adhere to. Nor did colors represent which clan or faction the samurai was fighting for. Color choice was not regulated, and samurai were free to use colors and patterns they enjoyed and could afford. However, prominent local samurai and clans could become known to other locals for preferring a certain aesthetic and could be identified as such. But as battles began to involve tens of thousands of samurai, opportunity of standing out with unique colors and patterns became difficult as the available number of colors and patterns were quite limited.
Leather and Rawhide
It is often difficult to tell if various aspects of a suit of armor are made of leather, rawhide, or metal as it generally either highly decorated or covered in a thick layer of urushi. For armored sections, rawhide rather than leather was utilized.
Rawhide, nerigawa, mainly used in the construction of kozane (scale lamellar) armor, though armor plate of rawhide “plates” do exist, especially towards the later half of the edo period. The rawhide utilized is very thick, usually around 3mm (1/8″), and come from specific sections of hide from cattle. These hides were then cut, punched, and lacquered with urushi to form the armored sections.
More supple leather elements were used in decorative elements such as printed and pattern leather called egawa. As well as in support areas such as structural stripes in haidate and to protect the ankle from wear while on horseback in suneate.
Iron
Most of this information comes from Gunbai: Ancient Japanese Warfare Blog . I recommend reading all 4 posts in the series about Japanese metalworking.
Despite excellent metallurgic knowledge and skill becoming commonplace within the world of weapons, armor was not prominently constructed out of metal plates until the middle of the 15th century. And, even then it did not typically follow the same trends found in weapons. In order to make an incredibly difficult topic slightly easy to digest, here some of the insights from The Gunbai Blog:
Japanese iron and steel development, quality, and usage were very comparable to contemporary artisans in Europe and China. There are massive variations in armor plates when trying to compare top tier expensive suits to munition grade items; as well as when comparing items that are potentially separated by centuries. In general most armors appear to have been made from cold worked low carbon (wrought) iron rather than higher carbon steel. When steel was utilized it was generally in the later half of the 16th century, in very expensive suits, and primarily in chest and head protection.
Thickness of plates also varied greatly with use and time period. A bullet resistant dou (chestplate) from the late 16th century could be as thick as 3.5mm (10ga) while a dou from the late edo period, 300 years later, being only 1.2mm (18ga). It is difficult to gauge the exact thickness due to armor being covered in a thick (>1mm) layer of usushi. Pictured to the right is an edo period dou where the metal is 1.2mm and the urushi 0.8mm giving a total thick of 2mm.
Kusari 鎖具足 (Chainmail)
kusari has been used in Japan for at least the last 1,200 years. It was likely introduced from Korean, but quickly developed into its own distinctively Japanese style. We know it was used during the Mongol invasion of Japan in the 1200s, but it become more common place as the centuries went on. Particularly during the warring periods of the Muromachi (1333-1568) and Momoyama (1568-1600) eras, and reaching its most common use during the edo period (1600-1868).
Early on, kusari was rarely used as any sort of primary armor. It was typically found connecting plates together, filling voids/gaps in armor, but never as a standalone free hanging piece of armor like its counterpart in Europe. In later periods it become much more prevalent in more advanced kote, suneate, and haidate designs. Eventually, during the edo period when large scale warfare had ceased, kusari, along with tatami armor, became the defacto defense against commonly faced bladed weapons.
Kusari was primarly made of iron and low carbon steel, and occasionally brass. The rings were laqucered with urushi, usually in black or red, to provide additional strength and rust protection. The finish mail was also stitched down to a fabric or leather foundation. Sometimes it would also be sandwiched between fabric/leather layers.
Both round and oval rings 1/8″ (3mm) to 1/4″ (6mm) in 20ga (1mm) to 16ga (1.3mm) wire.
Fabric
Silk, hemp, linen
