The theory on how this works is called the “additive color theory.” In this theory, when red and green are equally mixed, it makes yellow; red and blue make magenta; and green and blue make cyan. With many of today’s smart cellular phones, there are apps that can be down-loaded that can calculate color based upon the additive theory for photographers. blindness and fatigue. Neutralizing Bleach Neutralizer Applying too much sodium metabisulfite causes a problem too because it turns into sodium hydrosulfite with heat. Sodium hydrosulfite destroys dyes. Hence, reducing bleach can compromise spot dyeing too. After applying bleach neutralizers, if the pH is around 5.5, it will need to be rinsed and neutralize to a pH between 6.7 and 7.3. These pH readings can only be made by measuring the pH directly from the fiber. The electronic pH meter is the only practi-cal way of doing this. The pH Meter The second problem in spot dyeing is in knowing what caused the problem and if it is still present. Common household bleach, sodium hy-pochlorite, is the most common source for color loss in nylon. If any of its residues are still present, it will compromise the integrity of the color repair. Printers Color Theory The additive theory does not work for pig-ments. The additive dye theory will not work for printers and paint because it completely covers the surface. The primary colors for this theory are cyan, magenta, yellow and black. Neutralizing Bleach Frequently, sodium hypochlorite is self neu-tralizing, but one can never be too sure. If it has neutralized, the resulting pH will be around 5.5; if bleach is still active, then it needs to be neutralized with sodium metabi-sulfite to a pH between 6.7 and 7.3. Most coffee and tea stain remov-ers and browning treatments contain sodium metabisulfite which leaves a pH around 5.5. Conclusion Everyone can do color repair today. All they need is a pH meter, a color-meter phone app and some dyes. However, it is still recommended that one gets some training. IICRC has a two day training seminar that can get you started. CM Subtractive Color Theory Dyes work on the “subtractive color theory,” because they absorb some of the color from the additive theory. What is seen, are the colors that are re-flected back from a surface. This is the theory used by textile dyers. In this subtractive theory, red, yellow and blue are the primary colors. When red and green are mixed it makes brown, which is a tertiary color. Mixing all the colors in large equal amounts makes black. Remember that in the additive theory all colors make white and black does not exist in that theory or the other theory. This is why printer cartages come in cyan, magenta yellow and black. The Color Meter Smartphone app developers have now real-ized we need help too. The problem is in converting RGB numeri-cal values to RYB values. Both Android and iPhones now sell apps that can do this. With this latest development, now a color repair technician can make an electronic evaluation between a color loss and the sur-rounding yarns. This means the phone can see the quanti-ties of red, yellow and blue. This eliminates the problems with color Greener cleaners make a difference. Ours make a BIG difference. And they REALLY work. Visit us on-line, and take the first step toward a cleaner, greener world. enviro-solution.com Toll Free: 1-877-674-4373 FREE INFO: Reader Service 207 or CMMOnline.com/freeinfo www.cmmonline.com 21
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