c. Blood stains.
d. Inks.
e. Chemicals, such as acids, alkalies.
Food stains are usually due either to grease contained in soup, meat, milk, etc., or to sugar contained in candies or preserves, or to fruit acids contained in fresh fruits or sauces.
Wheel grease and lubricant stains are obtained from various parts of machines, like elevators, street cars, etc. After the cloth leaves the loom it often contains spots of grease, oil, or dirt stains due to drippings from the loom or overhead machinery. These are removed by means of liquids called solvents that dissolve the stain. Ether is the principal solvent used in the mill to remove small stains.
Very few people realize that vapors of cooked food and fat, unless carried out of a house, will condense and settle on fabrics in the form of a film which collects a great deal of dust. (A bad grease spot usually has a neglected grease spot for a foundation.) In order to break up this film it is necessary to separate the entangled dust. This is performed by some mechanical means, such as shaking and brushing.
The most effective method of removing a stain is to place a circle of absorbent material[24] around the spot to take up the excess of liquid. A white cloth should be placed under the fabric to absorb the solvent and show when the goods are clean. Then apply the solvent with a cloth of the same color and texture (satin is excellent as it does not grow linty) and rub from outside the spot to the center to prevent spreading. It is necessary to rub very carefully as excessive rubbing will remove the nap and change the color. One of the great dangers in removing a stain is that you may spoil the fabric. Therefore great care must be exercised.
The principal solvents are ether, chloroform, alcohol, turpentine, benzene, and naphtha. Each solvent may be used to best advantage on certain fabrics.
The commercial grades of the solvents often contain impurities that leave a brown ring after evaporation. This brown ring is very objectionable. Turpentine is used only in removing stains from coarse fabrics. Chloroform, benzene, and naphtha are used on ordinary silks and linens. Ether and chloroform are used to best advantage in removing stains from delicate silk, as they seldom affect colors and evaporate very quickly. Of course it must be borne in mind that when a stain is removed from a fabric that portion that contained the stain loses some coloring matter and feels rougher than the other part.