The word "chap" is recorded in English since 1844, as an abbreviation of the Mexican or Spanish words chaparajos or chaparreras. Words with similar roots include chaparro or chaparral, the evergreen scrub vegetation that can tear at a rider's legs and gave rise to the need for chaps.
The traditional pronunciation of the word chaps, when referring to this garment, is with a "sh" sound (as in shave), rather than "ch" (as in chime). This reflects the similar pronunciation of chaparral. The authentic pronunciation by both the working and rodeo cowboy of the American West is "shaps."
Chaps are sturdy leather coverings for the legs designed to provide protection from brush and fencing. They are most commonly associated with cowboy culture of the American west as a protective garment to be used when riding a horse through brushy terrain. Chaps have since become a staple in the sport of rodeo, mainly to accentuate the ride of the cowboy on bucking horses and animals.
Chaps may have antecedents in certain types of armor. However, the earliest form of protective leather garment used by mounted riders who herded cattle in Spain and Mexico were called armas, which meant "shield." They were essentially two large pieces of cowhide that were used as a protective apron of sorts. They attached to the horn of the rider's stock saddle, and were spread across both the horse's chest and the rider's legs. From this early and rather cumbersome design came modifications that placed the garment entirely on the rider, and then style variations adapted as vaqueros and later, cowboys moved up from Mexico into the pacific coast and northern Rockies of what today is the United States and Canada. Different styles developed to fit the local climate, terrain and hazards. Designs were also modified for purely stylistic and decorative purposes.
Chaps are usually worn over denim jeans or other trousers of heavy material. They have their own belt, and usually are fitted around the hips, resting below the belt loops of the trousers, which usually are held on with their own separate belt. Except for chinks and armitas, which are designed to fit above the boot, most chaps are long, fitting over the boot and draping slightly over the arch of the foot. Some designs are cut to hang long at the heel and nearly cover the entire boot except for the toe. Batwings, chinks, and shotgun chaps fit firmly but comfortably around the thigh, with shotguns continuing to fit closely all the way down the calf, though not so snug as to limit free knee movement. The shotgun design is a bit flared at the ankle to allow for the rider's boot. Batwings and chinks are not attached around the leg below the knee.
Chaps are intended to protect the legs of cowboys from contact with daily environmental hazards seen in working with cattle, horses and other livestock. They help to protect riders' legs from scraping on brush, injury from thorns of cacti, sagebrush. mesquite and other thorny vegetation, reduce the chance of rope burns, and reduce the dust load on clothing.
They are also used by western riders at horse shows, where contestants are required to adhere to traditional forms of clothing, albeit with more decorative touches than seen in working designs.
A specialized style of chinks without fringe, known as a shoeing or farrier's apron protects the legs of farriers from getting scratched or cut up in the process of shoeing or otherwise treating the hooves of horses. Farrier's aprons are also sometimes used by ranch hands when stacking hay to reduce wear on clothing.
An item of chainsaw safety clothing are chainsaw chaps, which are made of strong materials like kevlar and protect the legs from injury.
Motorcycle chaps are an example of the shotgun style. They are usually manufactured smooth side out, and generally provide all-around protection for the leg and have side zippers to allow them to be put on easily. They are popular in the biker and leather subcultures, providing protection from the wind and cold, as well as partial protection of bikers from cuts and scrapes in the event of a fall to the roadway. The correct pronunciation within the biker community is also "shaps."
Chaps, with the exception of woolies, are traditionally made of cowhide. The leather is tanned and dyed, and the hide is usually "split" so that the leather is supple and can be made into a garment that allows easy movement. There is a rough side, what is today called suede or "roughout," and a smooth side. Chaps are made in both "roughout" and "smooth out" (smooth side out) designs. Most batwings and chinks are made smooth side out, most shotguns are suede, or roughout. For horse shows, where fashions may change from year to year and durability is not as great a concern, lighter, synthetic materials such as ultrasuede and vinyl may be used for chaps, but they will not hold up as well. Even horse show exhibitors prefer real leather suede or a smooth split for durability and proper fit.
Most chaps, with the exception of Armitas (which have no metal parts), usually have a small metal buckle in front to attach around the waist, and have adjustable lacing on the back of the belt area to allow adjustment in size. The sides either have straps and relatively small metal buckles or snaps to attach the legging around the rider's leg, or else they have heavy-duty metal zippers.
Many chaps are fringed along the edge of the leg, usually a fringe of the same leather as the legging, though occasionally a contrasting color of leather may be added. Chinks and Armitas have fringe on the bottom of the leg as well. The belt that holds on a pair of the chaps may be the same color of leather or of a contrasting color, sometimes is fringed in the back for show, but usually not on a working outfit. Decorative leather designs or fancy stitching may be added along the edge of bottom of the leg or to the belt, and even sterling silver pieces may be used for buckles, and on round decorative metal conchos placed to cover the lacing on the back of the belt, or occasionally even at the bottom of the legging, by the heel.
Batwing chaps are cut wide with a flare at the bottom. Generally made of smooth leather, they have only two or three fasteners around the thigh, thus allowing great freedom of movement for the lower leg. This is helpful when riding very actively, and makes it easier to mount the horse. This design also provides more air circulation and is thus somewhat cooler for hot weather wear. Batwing chaps are often seen on rodeo riders, particularly those who ride bucking stock. They are also seen on working ranches.
Shotgun chaps, sometmes called "Stovepipes," were so named because the legs are straight and narrow. Each leg is cut from a single piece of leather. Their fit is snug, wrapping completely around the leg. They have full-length zippers running along the outside of the leg from the thigh to just above the ankle. The edge of each legging can be fringed and the bottom is sometimes cut with an arch or flare that allows a smooth fit over the arch of a boot. Shotguns do not flap around the way the batwing design can, and they are also better at trapping body heat, an advantage in windy, snowy or cold conditions, though unpleasant in very hot or humid weather. Shotgun chaps are more common on ranches in the northwest, Rocky Mountains and northern plains states, as well as Canada and are the design most commonly seen in horse show competition for western riders, especially western equitation.
Chinks, pronounced with a hard "ch" sound, are a type of half-length chap that attaches at the waist and stops just below the knee, with very long fringe at the bottom and along the sides. The word is derived from chinkaderos. The leg usually ends two to four inches (5 to 10 cm) below the knee. Chinks are usually fringed along the outside edge and bottom, making their apparent length about 4 inches (10 cm) longer. They are cut to fit somewhere between batwings and shotguns, and each leg usually has only two fasteners high on the thigh. They are cooler to wear and hence the design that is best for very warm climates.
Woolies are a variation on shotgun chaps, made with a fleece or hair-on hide, such as angora wool, lined with canvas on the inside. They are the warmest chaps, associated with states in the northern plains and Rocky Mountains.
The above paraphrased from http://en.wikipedia.org/wiki/Chaps
Interesting History of The Cowboy, Cattle Drives and Cattle Towns:
The term cowboy was first used in Texas in the 1860s to describe the work of men controlling cattle on horseback. After the American Civil War there was a great demand for meat in the northern and eastern parts of the United States. It is estimated that at this time there were over 5 million Longhorns in Texas.
The task of the cowboy was to take part in cattle drives where cattle were driven from Texas to the railroad cowtowns of Abilene, Dodge City, Wichita and Newton. The cattle business eventually spread to other parts of Kansas, Wyoming, Montana, New Mexico, Colorado and Arizona.
Cowboys were paid about ten dollars a week. After a long cattle drive they would often spend the money on drink, prostitutes and gambling in the railroad cowtowns.
(1) D. W. Wilder, Annals of Kansas (1882)
The typical cowboy wears a white hat, with a gilt cord and tassel, high-top boots, leather pants, a woolen shirt, a coat, and no vest. On his heels he wears a pair of jingling Mexican spurs, as large around as a teacup. When he feels well (and he always does when full of what he calls "Kansas sheep-dip"), the average cowboy is a bad man to handle. Armed to the teeth, well mounted, and full of their favorite beverage, the cowboys will dash through the principal streets of a town, yelling like Comanches. This they call "cleaning out a town."
(2) Kansas State Record (5th August, 1871)
Before dark you will have an opportunity to notice that Abilene is divided by the railroad into two sections, very different in appearance. The north side is literary, religious and commercial, and possesses... Wilson's Chronicle, the churches, the banks, and several large stores of various description; the south side of the road is the Abilene of "story and song," and possesses the large hotels, the saloons, and the places where the "dealers in card board, bone and ivory" most do congregate. When you are on the north side of the track you are in Kansas, and hear sober and profitable conversation on the subject of the weather, the price of land and the crops; when you cross to the south side you are in Texas, and talk about cattle, varied by occasional remarks on "beeves" and "stock." Nine out of ten men you meet are directly or indirectly interested in the cattle trade; five at least out of every ten, are Texans. As at Newton, Texas names are prominent on the fronts of saloons and other "business houses," mingled with sign board allusions to the cattle business. A clothing dealer implores you to buy your "outfit" at the sign of the "Long Horns"; the leading gambling house is of course the "Alamo," and "Lone Stars" shine in every direction.
At night everything is "full up." The "Alamo" especially being a center of attraction. Here, in a well lighted room opening on the street, the "boys" gather in crowds round the tables, to play or to watch others; a bartender, with a countenance like a youthful divinity student, fabricates wonderful drinks, while the music of a piano and a violin from a raised recess, enlivens the scene, and "soothes the savage breasts" of those who retire torn and lacerated from an unfortunate combat with the "tiger." The games most affected are faro and monte, the latter being greatly patronized by the Mexicans of Abilene, who sit with perfectly unmoved countenances and play for hours at a stretch, for your Mexican loses with entire indifference two things somewhat valued by other men, viz: his money and his life.
It may be inferred from the foregoing that the Texan cattle driver is some what prone to "run free" as far as morals are concerned, but on the contrary, vice in one of its forms, is sternly driven forth from the city limits for the space of at least a quarter of a mile, where its 'local habitation" is courteously and modestly, but rather indefinitely designated as the "Beer Garden." Here all that class of females who "went through" the Prodigal Son, and eventually drove that young gentleman into the hog business, are compelled to reside. In the amusements we have referred to does the "jolly drover" while the night away in Abilene.
Day in Abilene is very different. The town seems quite deserted, the "herders" go out to their herd or disappear in some direction, and thus the town relapses into the ordinary appearance of towns in general. It is during the day, that, seated on the piazzas of the hotels, may be seen a class of men peculiar to Texas and possessing many marked traits of character. We allude to the stock raisers and owners, who count their acres by thousands and their cattle by tens of thousands.
The above paraphrased from http://www.spartacus.schoolnet.co.uk/WWchaps.htm