With colour printing, it is important to remember that what you see on a screen will always be slightly different in print. Colour on a screen reacts to the brightness of the light behind it, where as ink will respond the brightness of the paper it is printed on. When approaching colour for print, you will notice there are a few different colour modes available including RGB and CMYK.
RGB is the colour system used for screen and stands for:
R – red G – green B – blue
Colour for print is always in CMYK format. Sometimes referred to as four colour or process colour. CMYK stands for:
C – cyan M – magenta Y – yellow K – black
CMYK enables each colour to be printed a layer at a time. CMYK printing uses very fine dots of colour, called a halftone, that once layered together creates a solid image. This layering system is used in offset printing to create your image, therefore all artworks going to print must be in CMYK format.
Pantone is simply a colour management system. It is possible to Pantone match colour for offset printing which gives you greater accuracy and options than digital. Because the inks are either used straight from the tin or physically mixed together, offset printing gives you a much broader choice of colour and therefore the ability to match colour exactly is very possible to achieve. Digital colour printing does have its limits, for example the ability to print in vibrant, fluorescent ink, or metallics is only possible with offset or screen print. Digital printing is generally used for smaller runs whereas offset is used for larger runs, this is generally because of the costs involved with creating individual plates. It is possible to create very unique prints with processes such as over printing by combining both CMYK with additional Pantone colours on top. Often a brand needs to match a colour exactly, for example on a logo, this is where Pantone is used to perfectly match the desired colour exactly, because they actually use Pantone inks.
A useful website to match your colour exactly is https://www.pantone.com/color-finder
This generates the code or number that can be matched in print. You can also view these within your artwork if using Photoshop.
By clicking on Colour > Colour Library
The term color density describes the optical density of areas printed in colour. This value is important when monitoring quality in printing processes. However, it is only ever possible to compare the color densities of an individual hue with each other.
The term colour depth (or bit depth) refers to the number of bits used to store the color information of a pixel in the pixel format.
Colour management refers to the control of color reproduction in a digital graphic production process. The various input and output devices from the scanner to the printing press support different colour spaces, depending on the device. In order to standardize the way colors appear throughout the production process, colour profiles are generated for the devices and processes involved in the process. The combination of these colour profiles makes it possible to calculate the coefficients necessary for data conversion. Those colours in a given color space that cannot be displayed in another are approximated as closely as possible.
The colour profile of an image input or output device (scanner, monitor, printer, printing press, etc.) is an element of color management which indicates how the color information supplied by the device behaves with respect to a superordinate, device-neutral color system (e.g. the CIELAB color space). Manufacturers supply color profiles with professional devices. To ensure high-quality results, profiles need to be created individually using special measuring instruments. This procedure may need to be repeated at regular intervals.
A colour proof is used for a binding, advance check of the colours of a printed product. It entails much less effort than a press proof on the press itself and can also be produced away from the printing site.
In addition, there has recently been a major drop in the price of printers that reliably produce high- quality color prints. The prerequisite for an accurate color proof is, however, the reliable control of the (electronic) preprint process with a color management system that also includes the press and the paper used.
A colour separation is the colour component of a digital print original which corresponds to a color in multicolor printing. The most popular four-colour printing process is the CMYK color model which requires four separations in the colours cyan, magenta, yellow and black for producing the corresponding printing plates. The colour separations which together form a complete colour original is known as a colour set.
A colour space is the set of all colors which can be portrayed by a single colour system. The colour spaces of the RGB and CMYK systems on the other hand are noticeably smaller. In addition CMYK data is only ever useful for a given printing process and cannot be used again in other output media.