ART BRUSHES History.—The brush, like many other hand tools, is simply an improvement on what the fingers can do. No attempt will be made to trace its exact origin, but among the remains of the Cro-Magnon race are found pictures on the walls of Dordogne that certainly required brushes in painting them. As civilization advanced and wider uses were found, the crude brush, made pos sibly with reeds, was supplanted by a bunch of bristles tied to a stick; from then the brush developed rapidly. From the pro ficiency of the Egyptians and Greeks, we know very little basic improvement has been made in the paint brush since 3000-2000 B.c. A greater variety of uses in the art of painting, as well as specialization in industry, has brought about every conceivable form of the brush, every kind of hair and setting, as might be expected when one considers that its use varies from that of paint ing miniatures to washing railroad cars.
Material.—In selecting the hair or bristle for a brush, the manufacturer uses that of many different animals and depends upon various countries to furnish such material. The most popu larly used type of bristles for the stiffer paint and art brushes are the French bristles. These are pulled from hogs of central Europe, are white, range from i in. to 4 in. in length, and form one of the best known types of the bristle brush. Russia also furnishes bristles, which are longer and heavier, and greyish in colour. The most plentiful of all, however, are the black bristles of China, which are divided into two groups : those coming from the north ern part of China, and called Tientsin bristles ; those coming from the southern part of China, and called Hankow bristles. Naturally in a cold climate, such as that of northern China, animals grow longer and finer coats, while the bristles of the animals of the warmer climate are found to be shorter and stiffer. Hankow stock comes from colder mountainous regions and is heavier and stiffer than Tientsin which comes from warmer climates even though, geographically Tientsin is farther north. The Tientsin bristles are used largely for varnishing brushes, and the Hankow bristles for paint brushes, a stiff bristle being needed to push a heavy pigment along. Besides bristle, other varieties of hair are used. Red sable is perhaps the most sought after. Sable is cut from the tail of the kolinsky, an animal whose habitat is Siberia and Russia. The pelts are used in fur coats. The hair is reddish yellow, does not exceed i z in. in length, and is noted for its remarkable springiness and fineness. It is employed mostly in the manufacture of fine water colour and oil colour brushes. Camel-hair is very important because of its wide use. The term is a misnomer, however, the commercial material that is generally known as camel's hair being taken from a species of squirrel that is also an inhabitant of cold countries like Siberia and Russia. The best grade of camel-hair comes from the Province of Kazan in Russia ; it is the softest of all the hairs employed in brush making. Its extreme length runs to about 3 in. and in colour it ranges through red, blue, grey and black. Badger hair is a popular type, used in fine finishing and varnishing brushes. It comes from the animal of that name, and has the distinction of being the only hair taken from the pelt of animals ; all others are taken from the tails. It is greyish in colour, with a black band about i in. from the tip. Fitch hair is like badger and meets similar uses. Brownish black, it is taken from a skunk.
Amongst the hairs that are not so popular are Russian sable, similar in length and quality to red sable, but dark grey in colour; bear hair, which looks very much like fitch; and black sable, which resembles fitch but is taken from a South American civet. Several types of Chinese brushes are made of goat hair.
Manufacturing.—In manufacturing paint brushes of hair, the brush-maker generally considers that the tanning of the skin is enough preparation. Bristle is treated quite differently. Chinese bristles are shipped to England and America, cased and sorted according to their native province only. The brush-maker must remove these, and sterilize and sort them before they can be utilized in making brushes. Every bristle or hair, with the ex ception of some that are adulterants in brush-making (like horse hair) has a flag end and a butt end. The flag is the tip that has grown out of the animal; the butt is the root. A bristle is similar to an elongated cone in shape, and the brush-makers test adultera tions of horsehair by rolling a bristle between the thumb and fore finger ; if it is genuine bristle, it will slowly roll out of the fingers at the flag end. Each bristle has a natural curve, and to remove this two bundles of bristles are bound end to end and tied with cord. They are then boiled for three hours, which action also sterilizes them. Copper screens are used with meshes of varying thicknesses to sort out the thick and thin bristles. The long and short ones are then sorted, the long ones being much more valu able than the short, after which the bristles are ready to be set.
Settings.—For every kind of brush, a slightly different process is used for setting. The leather-bound, metal-bound, cord and wire-bound, and wire-drawn brushes are the most common, and there are those set in rubber, cement, glue and pitch. Each has its purpose. The popular type of floor-sweeper and dust brush is an example of a pitch-set brush, the setting being a great timesaver for the brush-maker, and just as good for the purpose as a rubber setting would be unless brush is washed as it sometimes is. Pitch settings drop out (except in wire drawn construction) if block expands or contracts due to moisture. Brushes used in water, as calcimine brushes, and water colour brushes for art pur poses, are quite often set in cement, as rubber settings expand when wet and are liable to burst the metal ferrule surrounding the setting. Glue set brushes, while generally considered a cheap type of setting, are as serviceable where the brush is not to be used in water or anything that would dissolve the glue. Some brushes used in painting automobile bodies are glue set.
Process.—In making the average varnish brush, the brush maker proceeds as follows : He takes up a handful of loose bristle and lays it on a scale, removing or adding bristles until it meets the proper weight. This bristle is then picked up and rolled out with both hands, the rolling being done by the thumbs with the finger tips held together. To straighten the bristle, it is constantly passed through a metal comb fastened upright on his bench. After a few seconds of rolling and combing, his adept fingers have made all the flag ends point upward, the convex side of the bristle lying on his palms and fingers. With a quick movement the portion in the right and left hands are folded on one another, so that all the flag ends point inward. This end of the bristle is then inserted in a brass cup which has just the shape on the inside that the brush will have on the outside when finished. The bottom of this cup is V-shaped, the V being covered with emery cloth. This aids the bristle in standing up straight. The thumbs and forefingers are then used in shaping the butt end, while the lower end of the cup is pounded vigorously on the bench, to make the bristles range along the emery cloth in a two-sided chisel shape.
All brushes of any quality are cupped in this manner and not cut, as is the popular idea. This cupping preserves the flag or soft end of the bristle which does the most work in painting. The brush-maker now clips the butt end that is sticking out of the cup until it is level or even. When two or three turns are taken with a fine piece of thread around the bristles, they are released from the cup into the metal ferrule, which will be their final resting place.
The glue, pitch, cement or whatever "set" is used, is poured in the ferrule in the space where the handle will go and allowed to settle down through the bristle and dry. If the brush is to be rubber set, the ferrule is pulled up, exposing the butt end of the brush about three-quarters of an inch. The brushes are then stood on the butt end in a tray with a perforated bottom. This tray is laid in another tray which contains pure gum rubber in solution with benzol. This submersion in the rubber is timed with great accuracy and the specific gravity of the rubber watched carefully, as capillary attraction is depended upon to raise the rubber up the bristle. If the bristles are left too long in the solution, the rubber will creep too far up and stiffen it against correct use.
The brushes are now removed from the gum, allowed to dry, and then laid in trays containing sulphur powder, whence they go to vulcanizing ovens: Vulcanization takes longer with brushes than with any other article because a heat great enough to vul canize rapidly would injure the bristle. When the brushes are removed from the ovens, nothing remains but to pull the ferrule down in place and fasten the handles on. They are then put in a centrifugal machine which holds them by the handles and swings the bristle end around. This removes loose bristles, which were too short to catch in the vulcanizer.
Brushes of hair are shaped and cupped in a manner similar to those of bristle, with the exception of some very small art brushes that are shaped almost entirely with the fingers and lips. Art brushes require more rigorous rules as to the length and shape of the setting. There are one-stroke brushes, so named because their long stock and squared end permit a letterer to make Roman, Old English and script letters with one stroke. Designers, show card, letterers and retouchers are the names of some other typical art brushes.
Brushes set for water colour are generally fuller and longer than those set for oil, having a light liquid to deal with and the other a heavy pigment and oil. The metals in which art brushes are set must also be taken into consideration. Copper, because of its non-corrosive quality is favoured for water colour, as is albata (an alloy of copper and nickel), while oil colour brushes need no such favouring.
Through France and central Europe, the setting of brushes in quills has prevailed for years. This industry is handed down from father to son, and bids fair to remain in France because of the availability of the quills.
In some of the larger types of brushes, and particularly in leather-bound brushes, a wedge is set in the centre of the bristle.
This leaves a V-shaped space between the two sides of the brush that has a tendency to hold more paint and prevent so much dipping of the brush. The longer stocks are much sought after in bristle buying, an added inch in length sometimes meaning twice the price. A long stock brush wears down to the length of a cheap brush through use.
Types.—The illustrations show some specialized brushes. Fig. i shows a round and flat fresco painting brush. As these are used in water colour and sometimes on ceilings the stock is extra long to give a light touch, hold plenty of the thin liquid and prevent dripping. Fig. 2 is a typical water colour brush. It assumes this shape only when it is wet. Two types of liners or stripers are shown in figs. 3 and 4. Fig. 3 is a quill striper and fig. 4 a sword striper. The entire length of the hair in these brushes used in coach striping is laid flat to take up any tendency to wobble and leave a jagged line. Fig. 5 is a "brights" brush used in oil painting and set to make short crisp strokes. Fig. 6 is a stencil brush, while fig. 7 shows different styles of quill brushes. Fig. 8 is a badger blender for softening harsh lines in a painting and for graining and marblizing. Fig. 9 is a squared-end lettering brush called a rigger.
(B. CH.)