Thursday, October 6, 2011

Why colors sometimes don’t match

No device in a publishing system is capable of reproducing the full range of colors viewable to the human eye. Each device operates within a specific color space that can produce a certain range, or gamut, of colors.

A color model determines the relationship between values, and the color space defines the absolute meaning of those values as colors. Some color models (such as CIE L*a*b) have a fixed color space because they relate directly to the way humans perceive color. These models are described as being device-independent. Other color models (RGB, HSL, HSB, CMYK, and so forth) can have many different color spaces. Because these models vary with each associated color space or device, they are described as being device-dependent.

Because of these varying color spaces, colors can shift in appearance as you transfer documents between different devices. Color variations can result from differences in image sources; the way software applications define color; print media (newsprint paper reproduces a smaller gamut than magazine-quality paper); and other natural variations, such as manufacturing differences in monitors or monitor age

About missing and mismatched color profiles

For a newly created document, the color workflow usually operates seamlessly: unless specified otherwise, the document uses the working space profile associated with its color mode for creating and editing colors. However, some existing documents may not use the working space profile that you have specified, and some existing documents may not be color-managed. It is common to encounter the following exceptions to your color-managed workflow:

You might open a document or import color data (for example, by copying and pasting or dragging and dropping) from a document that is not tagged with a profile. This is often the case when you open a document created in an application that either does not support color management or has color management turned off. You might open a document or import color data from a document that is tagged with a profile different from the current working space. This may be the case when you open a document that was created using different color management settings, or scanned and tagged with a scanner profile.

In either case, the application uses a color management policy to decide how to handle the color data in the document. If the profile is missing or does not match the working space, the application may display a warning message, depending on options you set in the Color Settings dialog box. Profile warnings are turned off by default, but you can turn them on to ensure the appropriate color management of documents on a case-by-case basis. The warning messages vary between applications, but in general you have the following options:

(Recommended) Leave the document or imported color data as it is. For example, you can choose to use the embedded profile (if one exists), leave the document without a color profile (if one doesn’t exist), or preserve the numbers in pasted color data.

Adjust the document or imported color data. For example, when opening a document with a missing color profile, you can choose to assign the current working space profile or a different profile. When opening a document with a mismatched color profile, you can choose to discard the profile or convert the colors to the current working space. When importing color data, you can choose to convert the colors to the current working space in order to preserve their appearance.

About color profiles

Precise, consistent color management requires accurate ICC-compliant profiles of all of your color devices. For example, without an accurate scanner profile, a perfectly scanned image may appear incorrect in another program, simply due to any difference between the scanner and the program displaying the image. This misleading representation may cause you to make unnecessary, time-wasting, and potentially damaging “corrections” to an already satisfactory image. With an accurate profile, a program importing the image can correct for any device differences and display a scan’s actual colors.

A color management system uses the following kinds of profiles :

Monitor profiles Describe how the monitor is currently reproducing color. This is the first profile you should create because viewing color accurately on your monitor allows for critical color decisions in the design process. If what you see on your monitor is not representative of the actual colors in your document, you will not be able to maintain color consistency.

Input device profiles Describe what colors an input device is capable of capturing or scanning. If your digital camera offers a choice of profiles, Adobe recommends that you select Adobe RGB. Otherwise, use sRGB (which is the default for most cameras). Advanced users may also consider using different profiles for different light sources. For scanner profiles, some photographers create separate profiles for each type or brand of film scanned on a scanner.

Output device profiles Describe the color space of output devices like desktop printers or a printing press. The color management system uses output device profiles to properly map the colors in a document to the colors within the gamut of an output device’s color space. The output profile should also take into consideration specific printing conditions, such as the type of paper and ink. For example, glossy paper is capable of displaying a different range of colors than matte paper.

Most printer drivers come with builtin color profiles. It’s a good idea to try these profiles before you invest in custom profiles.

Document profiles Define the specific RGB or CMYK color space of a document. By assigning, or tagging, a document with a profile, the application provides a definition of actual color appearances in the document. For example, R=127, G=12, B=107 is just a set of numbers that different devices will display differently. But when tagged with the AdobeRGB color space, these numbers specify an actual color or wavelength of light; in this case, a specific color of purple.

When color management is on, Adobe applications automatically assign new documents a profile based on Working Space options in the Color Settings dialog box. Documents without assigned profiles are known as untagged and contain only raw color numbers. When working with untagged documents, Adobe applications use the current working space profile to display and edit colors.

Thursday, July 9, 2009

Color (Print) CMYK

Cyan Magenta Yellow, Key (Black), or often abbreviated as CMYK is the process of mixing pigments commonly used printing. Process Cyan Ink, Process Cyan, Process Yellow, Black mixed with the process of composition and color accuracy to produce exactly as desired. Even if some time is required, this color (CMYK) can easily be reshaped. CMYK color system is also used by many printers because of the economic underclass. This model, either in part or whole, are usually imposed in the picture with white background color (this color is selected, because he can absorb a certain length of the light structure). Such a model is often known as the "subtractive", because the colors to reduce color of white light.

In another model of "color additive", as well as RGB (Red, Green, Blue), white color to the color combination of additional primary colors, while the black color may occur without any light. In the CMYK model, the opposite applies: the white color becomes natural color of the paper or a background color, whereas black is the color combination of primary colors. To save money to buy the ink, and color to produce a darker black, was made a special black color replaces the combination of Cyan, Magenta and Yellow.

There are terms in Photoshop Gamut Warning, Gamut is a term for the area that could be covered by a particular color system. The term is out of gamut colors that can not be represented by the proportion of the basic colors you want to use the system. Problems out of gamut often occurs in the conversion of CMYK colors with RGB colors. Although designed to provide accurate color, the color region formed by the CMYK color system sometimes is not as wide as RGB color range. For example RGB primary color red is out of gamut of the CMYK color system. Many ways have been sought to pursue this difference, for example by using color lab system.

source: wikipedia

Thursday, July 2, 2009

Cetak Offset (Offset Printing)

Monday, June 29, 2009

Rotogravure

Rotogravure is a printing technology in the world. Rotogravure alone in the world of print graphics means. Or in layman language is the printing technology used to print media made of a flexible material (eg; various types of plastic, aluminum and paper and PVC). Materials to be printed is in the form of rollers or rolls. Results from the rotogravure printing is not directly can be enjoyed by consumers, but must go through several stages, as follows (eg manufacture of snack packs of children); 1. Plastic laminated printout by placing first in print rollers to laminate machine, then the plastic rollers are coated with adhesive and attached to other media in the form of "metalize" (a mixture of plastic material coated with aluminum). 2. Results that have been laminated rolls and then dried (in the "aging") first. 3. Rollers that have been dried and then taken to the machine "slitter", to cut long, wide rolls into a certain size in accordance with orders from the snack manufacturer. The above process only a brief description, behind it is still a lot of technology used in the world to produce a rotogravure packaging. Starting from design, making cylindrical tubes of iron, copper coating, making the picture above has a metal cylinder covered with copper, chrome coating, printing, inspection, lamination, slitting (cutting), making bags (if that orders sent form pockets) and many longer process therein. Because in the process changing the form of raw material into a material, usually this process is called process of "converting" or in other words, is "converting industry" As for some everyday examples of converting the result is, as follows: 1. 2 packs of instant noodle. Packaging of drugs (other than the capsule and syrup and eye drops) 3. 4 snack packs. Water bottle label bottled mineral water and isotonic (called shrink label) 5. Close mineral water drinks, etc. (cup lid) 6. Rotogravure and the like can also be used to produce magazines, folding box, gift wrapp and beverage labels with special equipment can be done in line. Excess rotogravure printing process compared to other can be used to print in rolls of a width ranging from 20 cm (labeling) to 1100 cm (vinyl floor) with a length of more than 5000 m depending on the material used. Similarly, the type of materials used vary widely, ranging from plastic film 12mc to 320 gsm cardboard. While the weakness of the rotogravure is not as sharp image quality offset and text structure formed from the dot.

source: wikipedia

Saturday, June 27, 2009

Print Filter (Sablon)

Print filter or what we usually call Sablon is one of the techniques of the printing process using screens (screen) with a certain density and are basic barbahan Nylon or silk. This screen is then given polafotoresis and lit, will form the parts that can be passed and not ink. negative from the previous design made. This cloth is stretched tightly in order to produce the printout screen and flat. Having given

The process of execution is by pouring ink on the screen and then washed using a palette or rakel made of rubber. One screen is used for one color.


Source: wikipedia

Sunday, May 24, 2009

PRINT MACHINE HISTORY

Forms a very simple printing can be found in China and Korea around the year 175 AD. Display an upside-down on the wood, and later bronze was created in this year. The tool is then spiked with ink and then placed on a piece of paper and gently rubbed with a bamboo stick.
Major breakthrough came in about 1440 by Johannes Gutenberg from the city of Mainz, Germany. Gutenberg created a method of casting pieces of letters on the alloy made from tin. These pieces can be pressed to the top of the page for printing berteks. Method of printing by Gutenberg's invention as a whole depends on several elements on technology combining several of East Asia such as paper, printing from wood blocks and printing may be transferred, Shen Bi creation, coupled with increased demand from European society for price reductions of books made of paper. This typing method lasted for about 500 years.
In the year 1424, Cambridge University library had only 122 books each have a value equivalent to a farm or vineyard. Demand for books is driven by rising literacy rates among the middle-class people and students in Western Europe. At that time, the Renaissance is still in early development and gradually eliminate the pastor kemonopolian the literacy rate.
At the time of printing of logs arrived in Europe at about the same time with the arrival of the paper, this method does not secocok methods used in the East for literary communication. Printing more matching blocks to China because of the position of writing letters is not critical, but the existence of more than 5,000 basic characters made the basic role of technology made Chinese printing technology that can move into inefficient and economically impractical, in terms of profits for Chinese publishers Ancient. This is different to the Latin alphabet, the need for precise alignment lines and a simple character who puts mold moveable as a remarkable progress for Western society.
The use of the printing press is a key difference that technology provides the advantage of European inventors their partners from China, which is based on the printing machine screws used in the production of wine and olive oil. This is a sophistication about the machine in the year 1000, a tool used to apply pressure on the flat field is a tool commonly used in Europe.

Printing as it developed in East Asia did not use the press as in the case of Gutenberg. Although the discovery of mold moveable in China and Korea before the Gutenberg printing press, the impact of the printing press and printed moveable in East Asia do not have such a big influence on Western European societies. This is probably because the number of workers involved in manipulating the thousands of very large porcelain tablets, or in Korea, metal tablets, which required the use of writing Chinese characters. However, hundreds of thousands of books, on subjects ranging from Confucian Classics to science and science, printed using the older technology of printing from wooden blocks, making the world's first printing culture.
The impact of the Gutenberg printing press in Europe is almost equal to the development of writing, the discovery of the alphabet or the Internet, to the effect on society. Like the writing does not replace talking, printing was never reached a position of total power. Handwritten manuscript continues produced, and various models of communication graphs continuously influence each other.
The printing press is also a founder of the set of factors that scientists simply telling their findings through the establishment of a scientific journal is widely disseminated. This helps them bring in the scientific revolution. Authorship became more meaningful and profitable because of the printing press. Suddenly it becomes important who is saying or writing anything, and what is the formulation and the appropriate arrangements. Does This allows the author to mention just a reference, which produces the rules, "One Author, one work (right), one piece of information" (Giesecke, 1989; 325). Previously, the author is not something that is important, since a copy of Aristotle made in Paris will not be identical to the original in Bologna. For many works prior to the printing press, the author's name as a whole lost.
Because the printing process ensures that the same information fell on the same page, the page is given a number, contents, and indices became common, although they had not previously known. The process of reading is also changed, gradually changing in a few centuries from oral measurements to a personal reading. The availability of large print materials also causes a drastic increase in adult literacy levels across Europe.
In the fifty or sixty years of the discovery of the printing press, all the classical rules are reprinted and distributed throughout Europe (Eisenstein, 1969; 52). Since more people have access to knowledge, both new and old, more people can discuss this work. Furthermore, since the production of the book is a more commercial companies law, the first copyright law passed to protect what is now called the rights of intellectual property. A second development was the popularization of knowledge of this decline in Latin as the language most published works, to be replaced by everyday language in their respective fields, add species published works. Paradoxically, in the printed word also helps to unify and standardize the spelling and syntax vernacular, and has the effect of reducing their diversity. An increase in the interest of national language against the people of Europe Latin mentioned as one reason for the increase of nationalism in Europe.
Print Machinery Gutenberg
Of Johannes Gutenberg printing press in the beginning around 1436 when he was working together with Andreas Dritzehan, someone who once guided by Gutenberg in stone cutting, and Andreas Heilmann, owner of paper mills. But the official record emerged only in 1439 when there was a lawsuit against the press; the witnesses who have talked about the Gutenberg printing, inventory metals (including lead), and mold ketikannya.
Communities in Europe at that time also is developing mold moveable, including goldsmith Procopius Waldfoghel from France and Laurens Janszoon Coster of the Netherlands. However, they are not known for having contributed specifically to the progress of the printing press.
Gutenberg was the first to create a mold from a mixture of lead, tin, and antimony are critical to produce durable prints that produces high-quality printed books, and proven to be more suitable for printing than the clay mold, wood or bronze, created in East Asia. This is a knowledge acquired at the time of Gutenberg's work for a professional goldsmith. To create a print of this interplay, Gutenberg uses something that makes discovery considered as the most ingenious invention, a special matrix allows the formation of new mold quickly and accurately than a uniform framework.
Gutenberg was also recognized for introducing the oil-based ink is more durable than water-based ink used once. For printing materials he uses a script that is made from animal skins and paper, the latter introduced in Europe from China by using the way the Arabs centuries ago.
In in his book, Gutenberg's printing press to make the experiment of color for some parts of the page, available only in some copies. New-new work, The Mainz Psalter issued in 1453, apparently designed by Gutenberg but was published in the issue of his successor, Johann Fust and Peter Schöffer, using the initial print of red and blue colored complex.
Life magazine considers Print Engine is the discovery of the most remarkable in the last 1000 years. It is important to realize that the alphabet may be the key to the success of the printing press.

source: wikipedia