National Clothesline

Fabric in its gray good stage may be gray or yellow. These fabrics are then bleached and fluorescent dyes are added to increase their whiteness.

Fluorescent dyes are optical brightness that converts ultraviolet light to visible light. Some brightly colored fabrics and prints can also be impregnated with a fluorescent dye to increase the brightness and brilliance of the colors used.

Fluorescent dyes are used in all types of fibers and fabrics. Color experts have distinguished approximately 300 shades of white. The brightest whites have a slight bluish hue.

Drycleaners usually handle a colored or dyed fabric with the precaution of first testing it. When it is a white fabric, the precaution is frequently overlooked because a white fabric is usually considered color safe.

Fluorescent dyes may break down when exposed to:

Light and heat. Household fabrics can discolor when exposed to both sunlight and artificial light. Garments are also affected after long exposure to either light.

Staining substances. Chloride salts found in perspiration and many foods can break down the fluorescent dyes.

Drycleaning. If drycleaning solvent removes the fluorescent dye the fabric may return in appearance to a yellowish, gray or pink color. Fluorescent dye loss due to drycleaning is more common in polyesters, cottons and linen. Do not blame the gray appearance caused by soil re-deposition on fluorescent dyes.

Pre-spotting chemicals. Wools and silks are adversely affected by protein formulas and ammonia. Tannin formulas and acids can affect the fluorescent dye on linens, rayons and cottons.

All white fabrics should be suspected of having been dyed with a fluorescent dye. Brilliant or vivid colored fabrics are also suspect.

Examine the fabric for yellowing or fading on the shoulders, neck line and other exposed areas. An ultraviolet or black light lamp is a sure method of identifying fluorescent dye. Under the lamp light fluorescent dye is bright but where the fluorescent dye has been adversely affected the area will show dark.

Staining substances which have also affected the fluorescent dye will show up dark. Drycleaners who own my portable Spectralight have an easy time of identifying fluorescent dyes.

Test wool and silk on an unexposed area before using protein formulas or ammonia. If yellowing or brown discoloration starts to occur when using these chemicals, discontinue the procedure. Flush the area immediately and apply a mild acid such as acetic or tannin formulas.

Consider using a digester for removing protein or albuminous stains. Always test strong acids such as general formula, oxalic acid and rust remover before using.

If a fabric starts to discolor when using an acid, flush it out immediately and use an alkali such as a protein formula or ammonia. Before using paint remover with water or the steam gun, the fabric must be tested on an unexposed area. Do not permit paint remover to dry on the fabric.

Some drycleaners mistake redeposition for a fluorescent dye breakdown. To test for re-deposition use the following procedures:

Apply oily type paint remover to an affected area.

Tamp.

Flush with steam gun.

Add oily type paint remover and ammonia.

Tamp.

Flush with the steam gun.

Dry with the air gun.

If the area becomes bright, the graying or other discoloration is redeposition.

Before attempting a correction procedure, test the area for effectiveness.

Test using hydrogen peroxide and ammonia. If this is effective, a soaking in sodium percarbonate should be used. Soak over night and use an acetic acid bath for neutralizing.

Test the area using sodium hydrosulfite. If this is effective, soak the item using sodium hydrosulfite with a neutral lubricant.

It may be even more effective to soak the item in a product such as Drogo, which is Wilson’s product that combines sodium hydrosulfite with a liquid fluorescent brightener.