Printing Company : What's CMYK color? And, What's RGB color?

Published Time:2016-02-17 Original Source:Printing Company : What's CMYK color? And, What's RGB color?
WHAT IS CMYK? And, What's RGB color? Let's tell you the differenence as in below:
WHAT'S CMYK?
CMYK color
CMYK refers to the four inks used in some color printing: cyan, magenta, yellow, and key (black). Though it varies by print house, press operator, press manufacturer, and press run, ink is typically applied in the order of the abbreviation. 
 
The "K" in CMYK stands for key since in four-color printing cyan, magenta, and yellow printing plates are carefully keyed or aligned with the key of the black key plate.
 
The CMYK model works by partially or entirely masking colors on a lighter, usually white, background. The ink reduces the light that would otherwise be reflected. Such a model is called subtractive because inks "subtract" brightness from white.
CMYK ink
WHAT IS RGB?
 
The RGB color model is an additive color model in which red, green, and blue light are added together in various ways to reproduce a broad array ofcolors. The name of the model comes from the initials of the three additive primary colors, red, green, and blue.
 
The main purpose of the RGB color model is for the sensing, representation, and display of images in electronic systems, such as televisions and computers, though it has also been used in conventional photography.
 
RGB is a device-dependent color model: different devices detect or reproduce a given RGB value differently, since the color elements (such as phosphors or dyes) and their response to the individual R, G, and B levels vary from manufacturer to manufacturer, or even in the same device over time. Thus an RGB value does not define the same color across devices without some kind of color management.
 
WHAT IS A SPOT COLOUR?
 
In offset printing, a spot color is any color generated by an ink (pure or mixed) that is printed using a single run.
 
The widely spread offset-printing process is composed of four spot colors: Cyan, Magenta, Yellow, and Key (black) commonly referred to as CMYK. More advanced processes involve the use of six spot colors (hexachromatic process), which add Orange and Green to the process (termed CMYKOG). The two additional spot colors are added to compensate for the ineffective reproduction of faint tints using CMYK colors only. However, offset technicians around the world use the term spot color to mean any color generated by a non-standard offset ink; such as metallic, fluorescent, spot varnish, or custom hand-mixed inks.
 
When making a multi-color print with a spot color process, every spot color needs its own lithographic film. All the areas of the same spot color are printed using the same film, hence, using the same lithographic plate. The dot gain, hence the screen angle and line frequency, of a spot color vary according to its intended purpose. Spot lamination and UV coatings are sometimes referred to as 'spot colors', as they share the characteristics of requiring a separate lithographic film and print run.
 
WHAT IS BLEED?
 
Bleed is a printing term that refers to printing that goes beyond the edge of the sheet before trimming. In other words, the bleed is the area to be trimmed off. The bleed is the part on the side of a document that gives the printer a small amount of space to account for movement of the paper, and design inconsistencies. Artwork and background colors can extend into the bleed area and after trimming, the bleed ensures that no unprinted edges occur in the final trimmed document.
 
For more information about bleeding on printing, please check this: What's a bleed/bleeding?