Color sample confirmation
1. Color sample self-evaluation
Use a gray card to match the color, and the required level between the original sample and the sample is 4.5.
When using a tester to match colors, generally △E<1. Considering the system error, the internal control standard △E< 0.6, and strive to get it right the first time. If the requirements are high, hue △H and chroma △C should also be taken into consideration.
It is necessary to fully understand the heat sensitivity and photosensitivity of dyes. There are fewer photosensitive dyes, and most dyes are more or less heat-sensitive. Shihlin dyes are more prominent. Cold, heat, dryness, and humidity all have an impact on the color and light. When making color matching with this type of dye, you must consider the stability of the dye’s color and light. The trend is to deviate a little in the opposite direction.
For example, the color of some dyes tends to be slightly darker in red after stabilization. When the color is slightly cold just after the sample is printed, the color should be slightly brighter in green, so that when the color is stable, it will be just the same as the original color. equal. Using dyes with severe photosensitivity and heat sensitivity as the main color proofing may cause color printing on mass-produced color cloths, which may even be irreversible in serious cases, such as olive green R, yellow C-2R and other dyes. Therefore, such dyes cannot be used.
Whether the prototype meets the customer’s requirements, you must be aware of regular customer proofing, and it is easy to make accurate samples based on customer habits. Different regions have different color preferences. For example, European orders avoid red and may prefer green light. Different consumer groups of fabrics have different color preferences. For example, children’s clothing generally likes bright colors; men’s clothing should be as neutral as possible, with low color saturation and darker colors; women’s clothing should be brighter, etc.
Generally, customers require at least 3 prototypes, namely samples A, B, and C. Sometimes, 12 samples are also required. Consider aspects such as depth, lightness, brightness, and hue to improve the first-time accuracy rate.
2. Approval of the sample
When the customer’s opinion is different from the actual situation, consideration should be given to If there is a possible light source problem, you should communicate with the customer. When the customer reports that most of the samples in a color palette are too dark, it should be considered that the customer may be comparing the samples in two layers, especially for thin and transparent fabrics. The laminated samples will appear darker. Some large companies require 4 layers of matching colors for thin and transparent woven fabrics and knitted fabrics. The norm is a single layer of color matching.
When the “jumping light” is serious, consider changing the dye to improve the “jumping light”. To understand the “metameric” properties of dyes, make full use of colorimeter to screen dyes. When the dyes applicable to our factory cannot meet the customer’s “light jumping” requirements or the “light jumping” is at △E<0.5, we should communicate with the customer.
Once the factory’s sample is confirmed and the confirmation sample is used as the reference sample, there will be no “light jumping” problem. Never choose a dyeing formula that is unstable in mass production just to meet customer requirements. When color matching small samples for direct production, you should try to color match under various light sources, such as D65 natural light and fluorescent lamps. There should be no serious “light jump”. If it is serious, please confirm with the customer before production.
3. Confirmation of large sample (head cylinder sample) production
Color light of large sample production According to the requirements, the customer’s approval opinion should be strictly followed, and the original sample should be used as the basis to deviate from the confirmation sample. It is best to persuade the customer to use the confirmation sample as the basis to deviate from the original sample. Because the fabric specifications of the confirmed sample are consistent with the large sample, it is easy to see the sample, the dye used is consistent, and there is no “jumping light” phenomenon. Generally, the color light is between the two, the gray card reaches level 4 or above, △E<1 (the internal control standard is generally △E<0.8), and customers will recognize it.
The batch difference is controlled above gray card level 4, the left, middle and right color difference is controlled above level 4-5, and the batch difference △E<1 (internal control 0 .Within 8). When choosing dyes, try to use dyes that are consistent with the sample prescription. Adjust the color light, and the newly added dye may cause a "light jump" phenomenon. When there is an obvious "light jump" between the large sample and the confirmation sample, there will be a risk of rejection of the large product, which will bring economic losses and reduced credibility to the enterprise. For example, when commonly used dyes with opposite spectrums, such as emerald blue, Shilin RB yuan, B green, T green, R red, etc., are used as added dyes, they should be handled with caution and check whether there is serious "light jumping" under each light source. If there is, it cannot be added.
When repeating and replenishing orders, the confirmation sample of the head cylinder is generally used as the basis to deviate from the original sample and the confirmation sample to keep the color and light of the entire batch consistent. However, sometimes customers insist on using the original sample or the confirmation sample. When confirming the sample as the benchmark, the color direction of the large product sample must be considered.
Post-finishing has an impact on the color light, and the color changes with different color lights. Therefore, after dyeing and setting out, the samples in the imitation finishing process need to adjust the color light and then dye them to meet customer requirements.
Common problems and countermeasures
1. Color fastness to light
When drawing samples in the laboratory, for color plates with light fastness requirements, dyes with good light fastness are required to be selected before making samples, including auxiliary colors, which must also meet the customer’s color. Fastness requirements. If in aIf there is a dye with poor light fastness in the formula, the light fastness of this color number will be reduced.
In addition, the compatibility of dyes should also be considered. For example, if Ciba Red C-2BL and Yellow CR-01 are used together, the light fastness will decrease, but when used separately , light fastness is very good. Although the light fastness of Shilin dyes blended with green FFB and yellow GCN did not decrease, it still caused brittle damage to the cellulose fibers. The preferred dye for dyeing light colors is Shihlin dye. The color dyed with Shihlin dye without reactive dyes will be full and even.
The light fastness on the dye color card refers to the ISO standard, and the test result is an 8-level system; American standard AATCC The standard is a 5-level system, and the difference is huge. The light fastness series on the dye color card refers to the series when the standard concentration is I:1. Therefore, when dyeing light colors with reactive dyes, it depends on the corresponding concentration series on the dye color card, such as 1/6, 1/12 , 1/25 and other indicators.
2. Metamerism
Light jumping is one of the most common problems in proofing . In actual operation, light color change and metamerism will be encountered.
Use a light box to check the “jumping light” situation, and initially select the dyeing to synchronize the “jumping light” from the accumulated experience prescriptions For prescription proofing, when a close dye formula cannot be selected from the accumulated color block samples, the original sample and the single-color sample are used to look for dye coloring samples with similar “jumping lights” under the light source.
With the help of colorimeter and colorimetric software, data calculation is performed between the standard sample and the single chromatogram, and the initial selection of dyes is used, which requires colorimetric technology and prediction experience. With the help of a color measuring instrument and color matching software, you can quickly find a dye formula that meets the light source requirements and is close to the customer, and intuitively and accurately know whether it meets the customer’s multi-light source requirements. There are many brands of color matching instruments, and there are certain differences in the measured data between them. If the “jumping light” problem cannot be solved, you can first transmit the “jumping light” situation of the color matching to the customer, and then solicit the customer’s opinion before making a sample.
Online ordering and online bidding have become commonplace in today’s social trends. Buyers will let multiple textile operating companies bid for one order, while marketers will place multiple orders. It often happens that two manufacturers produce swatches at the same time. Therefore, for enterprises, quick, accurate and good color samples are the first step to win orders. Improving product quality, accuracy, and stable color light is a test of the company’s strength and endurance, and is the foundation for the company’s sustainable development. </p
