Grantville Gazette - Volume V (38 page)

While the dyebath was being readied, the fabric was prepared for dyeing. Since it was received by the commercial dyer already scoured and bleached, the only step necessary was mordanting. A mordant is a chemical (most commonly a metal salt) that helps the dye adhere to the fabric. Fabric could be mordanted before, during or after dyeing. Since fabric was never dyed dry, it was common to use a mordant bath to wet the fabric before dyeing.

Once the dyebath was ready, the wet fabric would be lowered into it. The fabric would be drawn repeatedly through the dye to insure that the color would take up evenly. When either the desired color was achieved or the dyebath was exhausted, the cloth would be removed, rinsed thoroughly, and dried. Some colors required the fabric to be dyed multiple times.

A. Equipment and requirements (tools, fuel, location)

The two most important requirements for a dye house were plenty of clean, soft water and plenty of fuel. The location of the dye house was determined by this need for water and fuel. Dyeing required so much fuel, in fact, that many localities tried to limit the amount of wood bought by the dyers, restrict where it could be purchased, or ban the use of certain types of wood.

Ideally, a dyehouse had both a well with a pump and a system of pipes and troughs, and a nearby river. Soft water was preferred, as the minerals in hard water could affect the dye colors and the ability of the fabric to absorb the dye. The river was often used for washing fabrics (before or after dyeing) with the aid of a "dyer's raft" anchored in the river. There is record in the Hamburg archives concerning a hearing held to determine whether the dyers should be permitted to anchor a new raft after the old one was swept away during a flood. The council listened to testimony from local fishermen about the deleterious effect of the raft on the fish population. In the end, a new raft was permitted, but the dyers were forced to move it down steam, past the fishing grounds.

In addition to water and fuel, the dyers needed copper vats for preparing dyebaths, wooden vats for dyeing the fabric, furnaces for heating the water and boiling the dyes, hooks, rods, barrows and winches to move the fabric around, tools for grinding the dyestuffs, the dyestuffs themselves, mordants, and a building large enough to use and store it all. The building had to have a stone floor with provision for draining water and separate rooms for drying wet fabric and for storage. The roof had to be vented to allow steam and fumes to escape. Often, there would be a separate shed for storing fuel.

Setting up a dye house was an expensive proposition. In Nuremberg during the middle of the sixteenth century, the city council ordered a dyehouse built, with estimated construction costs of three thousand guilders. This was part of a series of expenditures made by the council to lure dyers from Antwerp to Nuremberg. All told, the council's investment totaled more than ten thousand guilders.

Home dyeing was simpler. All that was necessary was a pot for preparing the dyebath and some utensils for handling the hot, wet fabric. The modern home dyer uses inert pots and utensils dedicated to dyeing. The early modern home dyer probably used iron pots; whether these were dedicated to dyeing is unknown. The wet cloth could be lowered into the dyebath by hand, but once there a spoon or paddle would be needed to swish the cloth about and insure the color was absorbed evenly. Useful, but not required, would be some type of roller or wringer to squeeze excess dyebath from the cloth when it was done. Lastly, a place was needed to hang the finished product where it would be protected from dirt and dust while it dried.

B. Dyestuffs and mordants

i) Dyes: 

Dyestuffs could be found everywhere, but since most produced various shades of yellow and brown, those that produced reds, purples and blues were more valuable. After the discovery of the Americas in the fifteenth century and the establishment of the English East India Company in 1600, more exotic colors were available. Explorers were so aware of dyestuffs as trade goods that the country Brazil was named after the abundance of brazilwood found there. Not all the exotic dyestuffs were worth using, however. The red produced by brazilwood, for example, is fugitive, as is the lavender that comes from logwood.

The most common sources for reds, purples and blues during the early modern period were madder (red), murex (so called "imperial purple"), kermes (red), orchil (purple), woad (blue) and indigo (blue).

During the period between 1624 and 1627 in Frankfurt am Main, the cost of various dyestuffs ranged from about seven guilders per hundredweight for madder to two hundred and twenty guilders per hundredweight for indigo from Dominique. Between those two extremes, prices are recorded for galls from Aleppo at twenty-four guilders per hundredweight, woad from Erfurt at sixty guilders per barrel (approximately sixty pounds) and cochineal from Poland at about nine guilders per pound. Thus, it is clear that the price of the various dyestuffs varied widely.

The most expensive colors were black, blue and dark green, all of which required bottoming with woad or indigo first. The highest quality blacks were produced by "bottoming" fabric with woad until it was a very dark blue, then overdyeing it with madder. This combination made a color very close to a true black. Blue used woad or indigo alone, and dark green was produced by overdyeing blue fabric with weld, dyer's greenweed or a similar yellow dye.

Cheaper methods did exist to produce dark colors. Galls mixed with iron filings made black, black walnut shells produced a good brown, yellow bedstraw and safflower (when prepared as a vat dye) produced red. The home dyer may have experimented with reds and purples from beets and berries, too. Unfortunately, time has shown that these last produce only fugitive colors. Some of the colors produced by these cheaper methods were as good as the more expensive dyestuffs. Some, however, were not. Dyes containing too much tannic acid or iron damaged the fabric, eventually causing the fabric to disintegrate. Safflower red, like the berry colors, was fugitive.

Dyes such as galls, sumac, vitriol were banned in many cities and called "devil's colors" because of the damage they did to the fabric. As a measure to protect the woad trade, indigo also appeared in most lists of "devil's colors," even though it did not damage the fabric and, in fact, was a more efficient dye than woad.

ii) Mordants: 

In fact, most dyes were fugitive without the assistance of a mordant. Most mordants are metal salts, although there are a few, like tannic acid and tartartic acid, that are not. During the early modern period, the most common mordants were alum, copperas (iron) and blue vitriol (copper). All of the metal-salt mordants were toxic to some degree. Disposal of mordant baths and spent dye liquor into the nearest river led to fish kills and unnaturally colored streams.

A number of other chemicals were used in association with mordants, such as cream of tartar, urine, salt and vinegar. Some of these chemicals helped balance the pH of the dyebath while others helped assure the color was taken up evenly. The desired pH of the dyebath depended on the fiber being dyed, since silk and wool take color better in an acidic bath, while cotton and linen require an alkaline bath.

Fabric could be mordanted before, after or during dyeing. Most commercially dyed fabric was mordanted before dyeing, and then sometimes mordanted again, with a different salt, after dyeing. The combination of mordants and when they were applied both affected the final color. Many dye recipes from the Innsbruck manuscript, which contain the earliest known dye recipes in the German language, call for two or three different mordants to be applied.

Some dye plants also act as mordants, and would be easy for the home dyer to obtain. These include oak leaves, bark, galls and nuts, sumac or alder leaves, and black walnut shells. All of these alone produce brown and tan dyes. When combined with other colors, they would darken the original color. In addition, by using a copper or iron pot, the home dyer could simultaneously dye and mordant, thus saving a step in the process. Some modern dyers claim that dyeing in a reactive pot does not provide enough mordant to insure that the color will remain fast.

Club moss and seaweed, which contain alum, were also available to the home dyer, and where old wine barrels were accessible, the cream of tartar could be scraped from the inside of the barrels and added to the dyebath. Urine would also be a common mordant for the home dyer. It works better with some dyes than with others, and certain dyes, such as woad, require it. However, woad is not a mordant dye in the usual sense. It is a vat dye. The coloring agent is insoluble in water, and the dyebath is a solution of wood ash and rotten urine in which the woad has been fermented.

In addition to helping the dye bond with the fiber, mordants can change the color of the final product. Copperas (iron) and blue vitriol (copper) are said to "sadden" colors because they darken them and make them dull. Alum has very little effect on the color, which is one of the reasons it was so popular. Tin, which was first used as a mordant in 1630, brightens or "blooms" colors. Tannic acid tends to make colors brown. Other chemicals, while weak mordants by themselves, can be used to alter the effect of traditional mordants. Adding ammonia and probably urine causes yellow dyes to turn greenish. Vinegar both brightens and darkens colors.

The choice of mordant can make a dramatic difference in the final color obtained. Wool dyed with Dyer's greenweed and mordanted with alum produces a clear yellow, while wool mordanted with tin produces a dark blackish brown. Copper as a mordant with this plant and wool gives the yellow a greenish tinge.

Most mordants were sold by the hundredweight, with prices at Frankfurt am Main ranging from five guilders per hundredweight for Austrian red cream of tartar to thirty-three guilders per hundredweight for Aleppo galls. It is clear from the prices that quality varied with location. The price for Dutch alum ranged from seven to nine guilders per hundredweight, while the price for Bohemian alum was twice that.

Dyes and mordants were generally used at near boiling temperatures, filling the dyehouse with steam and fumes. Some of the materials in use, such as urine and fermenting plant matter, stank even at low temperatures. The addition of heat caused some volatiles to boil off, increasing the smell. Between the smell and the damage to nearby streams, dyehouses were not popular neighbors.

iii) The fiber: 

For the most part, dyestuffs produced the same colors no matter what fiber the fabric was made of. So woad and indigo turned cotton and linen, as well as wool, blue. Wool is the easiest fiber to dye, whether in the hands of the commercial or home dyer. It takes color well and is very reactive to the different mordants. Silk is also easy, and the colors, while perhaps not as deep as those in wool, are very vibrant. Both of these are protein fibers. Cotton and linen, on the other hand, are cellulose fibers, and until chemists and dyers unlocked the secrets of the Indian dyeing industry, cotton and linen tended to be paler and less vibrant. Fabric wasn't the only thing being dyed. Recipes exist for dyeing feathers, leather, wood and food.

While keeping in mind that no up-timer has knowledge of early modern dyeing, there are still areas in which Grantville's collective knowledge of modern chemistry could lead to changes and improvements. The following are some suggestions.

Speeding up the bleaching of cotton and linen. The article on bleaching in the 1911 Encyclopedia Britannica can be used as a starting point. That article traces advances in fiber bleaching.

Improving the purity of mordants. Mordants which could be relied upon to act in specific ways would be in high demand by dyers.

Improving the purity of dyes from woad and indigo. Synthetic indigo took a long time to develop. In the meantime, a dye of known strength and reliability would be a source of income for the developer.

A. Terminology

Adjective dyes: Dyes that require the presence of a mordant.

Bleaching: Removing the color from fiber. The people who did this were bleachers.

Bloom: The brightening of a dye by choice of mordant.

Bottoming: Dyeing cloth one color before overdyeing it to create a second color.

Bucking or bowking: Soaking fabric in an alkaline solution or series of solutions.

Dye: Coloring matter dissolved in solution.

Dye bath, dye liquor: The solution of dyestuffs and water.

Dyestuff: Plant, animal or mineral matter from which dye is extracted.

Fast dye: Dyes that do not appreciably fade over time or under the influence of sunlight.

Fix or fixing a dye: Making a dye permanent or fast.

Fugitive dye: Dyes that fade over time or under the influence of sunlight.

Fulling/fullers: Cloth is impregnated with fuller's earth and pounded, then rinsed. People who do this are fullers.

Grassing or crofting: Laying fabric out on the bleachfield and leaving it for weeks or months while the sun's action bleaches out the color.

Mordant: Chemical, often metallic salt, which assists in the bonding of the dyestuff to the fiber.

Napping/nappers: Finished cloth is brushed to raise the nap, and then the nap is sheared off. People who do this are nappers.

Sadden: The darkening of a dye by the choice of mordant.

Sericine: Silk is composed of sericine and fibroin; sericine is the component that causes the fibers to stick together, and which can prevent dye from being taken up by the fibroin.

Scouring: Cleansing wool.

Souring: Soaking cloth in a slight acidic solution to neutralize the alkaline bleach.

Substantive dyes: Dyes that are fast without need for a mordant.

Vat dye: Dye such as indigo or woad which uses a fermentation process to fix the color.