Additive Color

Color reproduction on the computer monitor (and on television) is achieved by combining Red, Green, and Blue light (RGB) in varying levels to produce a full color image. Red, green, and blue are the primary colors of white light and they cannot be produced by the combination of any other colors. When they are combined full strength, they will produce white light. The combining of red, blue and green colors is known as the "Additive Color Process", because when the colors of light are combined with one another, or added together, the result is an increase in light intensity. If none of the additive primaries are present, the color is perceived...

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Color

Color ConversionThe color gamut of RGB is broader than CMYK and the file size is smaller as well, but CMYK is the better choice for documents that will be used on the Web and for print. CMYK documents work well enough in the RGB environment, but RGB doesn't work as well in the CMYK environment.TrappingTrapping can help compensate for registration problems by slightly expanding one color into another and eliminating the gaps and color shifts between colors. PDF stores the trapping instructions in such a way that the trapped images will look the same on any computer and also when the images are output.For trapping to be effective, it must compensate...

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Color Bar

Color bars are also referred to as color control bars, color control strips, or proofing bars. Color bars are rows of different colored patches printed in the trim area of the press sheet. They are used by proofers and press operators to control the trapping, ink density, dot gain, and print contrast of the proof or the printed sheet. They usually consist of solid and tint blocks of cyan, magenta, yellow, and black; two and three color solids and tints; and additional elements and patterns such as resolution targets and dot gain scales.Solid process colors ofBlack, Yellow, Cyan, andMagenta. A color bar are used to measure ink densities.Solid...

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Spot Color

The colors used on spot color proofs are also known as "matched" colors, special colors, or by one of the brand names "Pantone" or "PMS" colors. Spot colors are printed from a single ink on a separate printing unit of the press. Spot colors can be standard, pastel, fluorescent or metallic colors. Several colors can be printed in select areas to create two, three or more color jobs. Spot colors can be used on may types of jobs, such as business cards, letterheads, forms, brochures and direct mail pieces. There are several variables involved with spot colors. A few manufacturers create color guides such as binders, chips, and fan books to show...

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Color Separations

In order to reproduce or prepare a full color image for printing using four process colors, the image must be divided into the the individual subtractive primary color components. The separation process can be accomplished photographically or electronically. Photographic Separations: Using a large process camera, a full color image is converted into halftone negatives which contain a series of dots of various sizes to represent shades of gray. The dots are achieved with the use of special screens placed over the negative material during exposure. When printed, the smaller dots create the lighter areas of the image, with the lightest appearing...

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Common problems encountered in Offset printing

Here is a list of problems that need to be paid attention to during the process of offset printing:Uneven colour: Always make sure that the colour is the same on both sides of the sheet by rolling the sheet up so that you can look at opposite edges of the sheet side by side.Ghosts: These are eitherImages formed in areas where they should not appear, orFormation of lighter areas where there should be even inking. Hickies (aka Fish-Eyes): These arenon-inked circles created by lint on the plate or blanket. They are generally something that can be cleaned up when appearing on several sheets in a row. However, chances are you will never be able to eliminate every single hickie, especially if you have large solids in your printing piece and have to print thousands of sheets.Picking: These are the...

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Three Color Printing

Theoretically it is possible to produce an adequate range of colours using just Cyan, Magenta and Yellow. However, three colour printing may also refer to the use of either.Three special inks orBlack combined with two special inks The Four Colour Printing Process, which is a system rarely used today, uses a black plate to add shade and depth reducing the amount of ink requir...

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Four Color Process Printing

Four colour process printing is the most common system for producing full colour print. In fact, the vast majority of magazines and colour books are produced using the four-colour process.Originally the artwork and originals had been separated using filters and four printing plates were produced.The four colour process printing consists of four ink colours namely, Cyan (Blue), Magenta (Red), Yellow and Black and is often referred to as CMYK. The inks used for four colour process printing are translucent due to which they can be overprinted and combined in a variety of different proportions to produce a wide range of colours....

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Advantages of Offset Printing

There are many advantages to offset printing namely:Economical-It is less expensive, especially when there are large quantities involved.Widespread Usability – It can be used on the widest range of printing surfaces, including paper, wood, metal, even leather.Ease of creating the printing plates.The paper does not have to be rated for the high temperatures and stress of either the copiers or laser printe...

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Offset Printing Process

The process of offset printing:Offset printing has been the most common form of commercial printing for the last sixty years. The most important element of the offset printing process is a plate manufactured from metalor polyster. This plate carries the copy of the image to be printed. The process of printing takes place as follows:The plate is chemically treated so that water may be absorbed only by the non-image areas of the plate.The plate is next attached to a plate cylinder, which rolls past the water roller. At this stage, the water on the water rollers is absorbed by the non-image areas of the plate, i.e. the areas not requiring ink.The cylinder next rolls over the ink roller. At this stage, the ink on the ink rollers sticks to the areas of the plate that are free of water.The rubber...

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What is Offset Printing

Offset printing is a printing process in which the inked image is transferred (ie, "offseted") from the plate to an intermediate blanket before being printed on the substrate. Following are the common terms you come across in offset printing.Opacity - This refers to the quality of being impenetrable by liquids or light. With paper, it refers to the ability to keep print from showing through to the other side.Opaque - In production it refers to a solution or paint used to block out areas on a film negative to keep them from being reproduced on the plate.Overprinting - It generally refers to printing an image over another impression. It also refers to printing a secondary color over a primary color in graphic arts wo...

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