Color standard application (three)
We are a big printing company in Shenzhen China . We offer all book publications, hardcover book printing, papercover book printing, hardcover notebook, sprial book printing, saddle stiching book printing, booklet printing,packaging box, calendars, all kinds of PVC, product brochures, notes, Children's book, stickers, all kinds of special paper color printing products, game cardand so on.
For more information please visit
http://www.joyful-printing.com. ENG only
http://www.joyful-printing.net
http://www.joyful-printing.org
email: info@joyful-printing.net
What data should I get when measuring color code?
Various printing markets, including publishing, cold-set advertising, newspaper printing, and business printing, have specific density values and dot gain requirements. Although the actual values will vary with each production process setting, the GCA Print Properties Committee conducted a survey in 1991 that shows that the target values listed in the table below have a copy of the print copy of the publication. The meaning of sex.
Element 100% (in the field) Printing contrast 50% expansion point expansion 25% expansion point
Green 1.25 30% or higher 24% 20%
Product 1.30 30% or higher 24% 20%
Yellow 0.98 25% or higher 22% 16%
Black 1.65 33% or higher 28% 24%
Note: The values in the above table are industry averages and will vary depending on factors such as paper, ink, press, press operator, and plate type. Also note that these values are very effective for copying high quality prints, but do not necessarily disregard the appearance of the image rather than achieving such absolute data.
Is it better to measure the color code during printing or to measure the color code when proofing? Which effect is better?
In fact, sensible print operators or color separation personnel do both. Many people in the industry should know that "no one buys numbers, they buy beautiful images." In the long run, they are right. Samples or prints with specified density values or dot gains may not achieve the desired appearance, in which case experienced color separation personnel or print operators – with the support of knowledgeable print customers – will make the necessary Adjust to get the look of the image you need. However, these color separations, print crews, and print customers will use color scale measurements to record the process adjustments needed to achieve the desired image reproduction. It is also important to note that the specified dot gain values, such as those provided in SWOP (Rotary Offset Parameter Description), SNAP (Newspaper Offset Parameter Description), and other documents, generally provide an optimal starting point for image reproduction. After reaching these target points, the printing operator evaluates the image effect, and then appropriately adjusts the ink key to change the appearance of the copy to finally meet the customer's needs.
Should the color code be attached to the back of the machine or pre-sample?
No. The original color-coded film should be imaged simultaneously with the image being proofed and placed side by side with the proofed page or ad. In addition, in the sample, the color code should be placed parallel to the press cylinder and run through the full length of the image to be proofed in order to provide valid information.
Can I copy or copy the color film?
No. Investigations conducted by the CGA Prepress Committee have shown that in most prepress operations, the use of copy and copy color scales does not effectively control the process. This is because the chroma value of the copied or copied color-coded film has undergone a certain change, which affects the practicality of the color-code as a copying process information transfer tool. Even if the copying conditions are set very carefully, the chromaticity value may change by 1% to 2%, which means that 50% of the chromaticity value on the original color scale will become 48% or 52% on the replica. Chromaticity value. Visual sensory factors such as measurement of dot gain and gray balance often rely on the surveyor's knowledge of the correct color-coded film values. If these values change due to factors such as copying or copying, the measurement results will not truly reflect changes in the process and prevent accurate communication of process information. There are three disputes about copying and copying the original color-coded film:
· Costs Color-coded film is very expensive, and a unit may require multiple sets of film, thus placing a certain burden on the enterprise. However, the results obtained by measuring with incorrect color-coded film, the control of the process often leads to the wrong transmission, shutdown and waste of information, compared with the cost of purchasing multiple sets of original film to meet the needs of the printing enterprise. The cost is still very small.
· Time Progress Sometimes the urgent need for color-coded film and the lack of access to the channel are one of the reasons for copying or copying film. The solution is to plan ahead or save enough spare film on hand.
· Confidence Some organizations have confidence that their prepress department can accurately copy or copy the color-coded film from the outlet to the outlet. According to this point of view, the ability of the operator to copy or copy the color separation film under certain control can be applied to the color standard film, thereby obtaining a better effect. But the facts show that this view is incorrect in many cases. It is necessary to make precise measurements to determine the extent of the changes caused by copying or copying.
Here are four other reasons to confirm that copying or copying color-coded film is unwise.
(1) Any copying or copying of the color-coded film will cause unnecessary changes to the measurement process, although the extent of this change may be small.
(2) For standard changes caused by the copying or copying process, the color-coded film is more sensitive than the color separation film. In fact, the print copy process is more tolerant of color separation film copy or copy changes than to color code film copy or copy changes. Many surveys have shown that color separations can be replicated more (or heavier) or finer (or lighter) while the ink and dots are more balanced, still satisfying the customer's color. Subjective requirements for copying. In contrast, color-coded film should be measured objectively and must be produced within tight tolerances.
(3) Copying or copying the color code can give the operator and management personnel the wrong information, which is easy to mislead the operator.
(4) The company lost the tools to control the exchange of information on precise process data. Unless all of the color-coded film is manufactured by the factory, operators, managers, quality control personnel, and customers cannot know exactly which color-coded film is used. Therefore, the real situation of the printing process is likely to be confused by the measurement results, resulting in undesired process changes. In the worse case, all objective measurement results need to be used as unreliable and non-essential data for stable high quality printing. Eliminated. Multiple copies of the color-coded film can only exacerbate the unreliability of the color-coded measurement tool.
How do I know if a color patch has been copied or copied?
There are two ways. The first method, using a magnifying glass, checks each thin line contained in the color stop or GATF Star Target element to see if they are degraded or degraded (for example, a thin line, a highlight or a dark point, or a thicker, or These elements are completely gone or blocked). In the second method, the chromaticity value of the color patches in the printed primary color is measured using a transmission densitometer, and it is detected whether or not the color patches are different from the expected values.