Three primary color dyeing is the most common method, and many customer samples can also be dyed with the three primary colors. If the properties of the three primary color dyes used in the customer sample are similar or consistent with the dyes used for proofing, there will be little or no metamerism. heterogeneous phenomena. General dye manufacturers will recommend three primary color combinations with different dyeing depths based on the directness, migration, diffusion, lifting, reactivity and other indicators of each dye. Here are eight ways to color the three primary colors.
After choosing a dye, you need to obtain the first prescription. There are generally two ways:
One is to use computers and software to The computer automatically searches for the closest first prescription in the database previously entered into the computer; or based on the color data (also called monochrome data) of different concentrations of each single dye entered into the computer, the computer calculates the first prescription.
Second, it is obtained based on the retained historical sample cards. Many experienced colorists usually accumulate a lot of historical sample cards. After the customer’s sample comes, they can look through it to find the closest historical sample card, and get the first prescription after correction.
Continuous pad dyeing processing methods, three primary color dyeing methods and eight methods
1. Percent addition and subtraction algorithm
Percent addition and subtraction algorithm is the basic algorithm in color grading. For example, the mass concentration of a certain dye used for proofing is 1 g/L. At this time, visual inspection or computer color measurement believes that it should be increased to 1.1 g/L. According to the algorithm, 10% should be added.
2. Transposition method
The transposition method is mostly used for color adjustment. When larger. For example, if you use 0.5 g/L of a certain dye for proofing, and after checking the customer sample, you think it should be increased to 1 g/L, that is, an increase of 100%, then you can use the customer sample to check the sample to see if you want to use the customer sample as the dye. Subtract 50% of 1 g/L to the color of the sample. This allows the accuracy of the color correction to be verified and corrected.
3. Pincer attack method
The pincer attack method starts from the Find the location of the customer sample among multiple samples. For example, the dye dosage for sample A is 0.8 g/L, and the dye dosage for sample B is 1.1 g/L. After checking the customer sample, it is found that sample A is lighter and sample B is darker. At this time, the customer sample is placed between A and B. Visually, the distance difference between the color depth of the customer sample and sample A is twice that of sample B. In this way, the amount of dye used is about is 1 g/L.
4. Depth first, then hue
Human eyes compare colors Among the three elements, hue is the most sensitive, followed by purity, and lightness is slower. The color of the same dye will change at different concentrations, especially darker colors. The darker the blue, the redder the color. Moreover, the dye reaches saturation after dyeing to a certain depth. Even if the amount of dye is increased, the amount of color obtained will not increase.
If the hue is the same but the depth is different during color matching, increasing or decreasing the dyes in the color matching in the same proportion will often lead to changes in hue and light.
So, if you first adjust the depth while ensuring that the hue is close, and then adjust the hue, the dye used for subsequent adjustments will increase or decrease very little, and the human eye will not be able to detect the depth. changes, but the changes in hue are clearly reflected.
Generally speaking, as the depth of bright red increases, the color becomes yellower; as the depth of maroon increases, the color becomes bluer and black; as the depth of sapphire blue increases, the color becomes darker. Red; as the depth of black increases, its color becomes more reddish and yellow; as the depth of brown increases, its color becomes bluer. Once you have mastered the law of color changes with depth, you can also adjust the depth and hue at the same time, and the color adjustment efficiency will be higher.
5. Stepping method
The stepping method has been The location of the customer sample can be deduced from the multiple samples produced. For example, the dye dosage of sample A is 0.7 g/L, and the dye dosage of sample B is 0.9 g/L. For the customer sample, the dosage of A and B is not enough. Visual inspection should increase the dosage from sample B to customer sample. The amount should be increased from sample A to sample B. Half, the dye dosage at this time is: 0.9 g/L+(0.9-0.7)/2 g/L=1 g/L.
6. Computer color matching
When the dyeing process conditions are fixed, When the system is controlled and the input data is correct, computer color matching will have higher accuracy and stability. However, in practice, especially in workshop production, the effectiveness of computers will be greatly affected by various uncontrollable factors. Therefore, on the one hand, we must continuously strengthen and improve the controllability of production conditions, and on the other hand, we must strive to reduce the randomness of human operations, so that the role of computer color grading can truly be brought into play.
7. Absolute law
The absolute method is based on a full understanding and clear memory of monochromatic data. It is mostly used when a new dye needs to be added to the color mix. This dye has not been used in previous color mixing, so of course, percentage addition and subtraction cannot be used. If the amount of newly added dye is relatively large compared to the main dye, the dye should be selected by computer color measurement first to prevent metamerism. For example, the red light of the small sample is different from the customer sample. At this time, visual inspection of the color depth of 0.1 g/L of a certain red dye can fill the gap between the small sample and the customer sample, that is, adding 0.1 g/L of this red dye to the color mixing prescription.
8. Relative method
The relative method is mostly used when a new dye needs to be added in color mixing. The premise is that the shade, strength and lifting power of each dye are fully memorized and understood. For example, in the sample formula, the dosage of dye A (strength 200%) is 10 g/L, and the dosage of dye B is 1 g/L (strength 100%), then the main dye is dye A, and dye C needs to be added between the sample and the customer sample ((strength 100%), and the dosage of dye C is considered to be 2% of the main dye A under the standard strength. At this time, the dosage of dye C in the prescription is: 10 g/L × 2 % × (100%/200%) = 0.1 g/L. This method is generally used in conjunction with the absolute method to improve the accuracy of the color prescription.
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