Photometer

Defined as a measuring device that calculates light, photometers come in different types and can be used in houses, cameras, prints, etc. Their function is to detect the amount of photons (light) being transmitted to a specific light source without fixing any detailed wavelength data. It is also used in comparing the different degrees of light produced. Spectrophotometers, on the other hand, which can be used in printing, provide elaborate wavelength data, which allows the analysis of samples' properties and the amount of light absorbed by the sample. See more.

You can see an example of the photometer and spectrometer process below:

A picture of a Spectrophotometer

Prepress

All the operations are to be realized before sending to printing media, preparation of the files, printing plates, negatives, etc. For instance, profiling printers (ICC profiles) and reducing artifacts are important steps that have to be done before the printing process. See more.

Printer controller

A printer controller is a workstation that manages the printheads, carriage movement, and all fluids-related systems. These controllers collect data from computers, which allows efficient digital communication between the two. Whether you have a WiFi or a USB connection, it is possible to install a printer driver on computers. The driver will let the computer search for the necessary data generated from the printer.

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Reference White

Also known as a spectralon, it is a material used for “reference white” that should be stable from one calibration to another. It is used for spectrophotometer calibration and is given as a base with the device (i1Pro2) or as a piece that can be changed in the device head (TotalColor). It has to reflect light at all angles equally, creating a nearly perfect diffuse reflection. No matter the angle of the fiber optic input, the instrument will receive the same amount of light.

Relative Colorimetric

This mode manages the white point difference between the input and the output devices. In case a color in the current color space is out of gamut in the target color space, it is reproduced to the closest possible color within the gamut of the target color space. This does not affect the colors already present in the gamut. The change implemented by the relative colorimetric is only applied to the colors that are absent in the destination gamut. This rendering intent can make two colors, which appear different in the source color space, similar to the target color space.

RGB

It refers to the Red, Green, and Blue colors. It is a mode of color composition that relies on the three colors to produce other visible colors in the color space. It is mostly used by monitors and scanners, and mixing the three basic colors with equal intensity generates pure white. More info.

RIP

A Raster Imaging Processor is a system that allows the conversion of a graphic file into an image raster for visualization and printing. The RIP is familiar with the capacities of the peripheral (like the resolutions, available qualities, or mechanical parameters). Large and Grand Format RIP software includes pre-press tools like ICC profile creation, nesting, tiling, and other modules. You can take the example of CalderaRIP to better understand Raster image processing.

Resolution

It is used to measure the quality accuracy of a printed or displayed image. Technically, it helps us determine the amount of horizontal and vertical pixels available in a given image. For instance, in printing, we use the label DPI (dots per inch) to refer to the image resolution. On the other hand, we use the PPI label to refer to the image quality displayed on screens.

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Resolution (horizontal):

This refers to the number of dots (dpi) or pixels (PPI) reflected from the left to the right on a specific image. The horizontal dpi is a function of the carriage speed in inches per second and the firing frequency of the jets: dpi Horizontal= frequency (Hz) / carriage speed (IPS). (R. J. Sullivan in Printing News, 2010). If the horizontal resolution is set to 500 dpi, this means that the printer will lay out, horizontally, 500 dots per inch on the media or paper used.

Resolution (vertical)

The vertical resolution completes the horizontal one and makes it ready to use for print. These resolutions are dependent on the native resolution of the printhead (R. J. Sullivan in Printing News, 2010). 

Resolution (native)

The native resolution is most commonly used to describe the space between the nozzles within a printhead. The nozzle spacing is converted to dots per inch to find the native resolution of the printhead ((R. J. Sullivan in Printing News, 2010). 

R. J. Sullivan in Printing News, 2010

Resolution (True) 

True resolution is not considered a very practical process due to the white space found between dots. To fix this and to tackle the absence of overlaps in true resolutions, we must add some overlaps to achieve optimal color density. Additional overlap is also required to account for errors in drop placement. More accurate drop placement will minimize the need for overlap resulting in less ink usage and the ability to print even fine text" (R. J. Sullivan in Printing News, 2010).

Resolution (Addressable)

"Some inkjet printers can accurately place dots with closer spacing and more overlap" (R. J. Sullivan in Printing News, 2010). This is known as an addressable resolution which will help in generating a higher quality image and greater color density. Even though using true resolutions by limiting ink drops and making them smaller is ideal, addressable resolutions can also be an efficient way to improve image quality and extend the number of possible applications.

Resolution (Apparent)

Finally, and also quoting R. J. Sullivan in Printing News (2010), we have the apparent resolution: "Image quality is further improved with light color inks by reducing graininess and is most noticeable in images containing smooth gradients, skin tones, and pastels". See more.

Rosette

A screening Pattern that is used in traditional offset printing to place ink drops according to a certain inclination angle. Formed in the Cyan, Magenta, and Black halftone screens, the rosette comes in two types: dot-centered and clear-centered. When rotated to their standard angles, halftone screens form a dot-centered rosette. The clear-centered rosette, on the other hand, is formed by shifting the black screen one-half a row of dots from the Magenta, Cyan, and Yellow screens. You can see the pattern below: 

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Solvent Ink

Solvent ink is also called Strong-Solvent when it is compared to Eco-Solvent. The solvent is usually used as a vehicle in the ink composition. Strong solvents have an important amount of volatile organic compounds (VOCs) recognizable by their smell and that require ventilation and extraction to protect the operators. It is mostly used for outdoor signage applications. More info.