Screen printing is a printing technique whereby a mesh is used to transfer ink onto a substrate, except in areas made impermeable to the ink by a blocking stencil. A blade or squeegee is moved across the screen to fill the open mesh apertures with ink, and a reverse stroke then causes the screen to touch the substrate momentarily along a line of contact. This causes the ink to wet the substrate and be pulled out of the mesh apertures as the screen springs back after the blade has passed. One color is printed at a time, so several screens can be used to produce a multicoloured image or design.
The CMYK color model is a subtractive color model, used in color printing, and is also used to describe the printing process itself. CMYK refers to the four inks used in some color printing: cyan, magenta, yellow, and key.
Dot matrix printing, sometimes called impact matrix printing, is the process of computer printing from a collection of dot matrix data to a device, which can be one of:
Inkjet printing is a type of computer printing that recreates a digital image by propelling droplets of ink onto paper, plastic, or other substrates. Inkjet printers are the most commonly used type of printer, and range from small inexpensive consumer models to expensive professional machines.
A printed circuit board (PCB) mechanically supports and electrically connects electronic components or electrical components using conductive tracks, pads and other features etched from one or more sheet layers of copper laminated onto and/or between sheet layers of a non-conductive substrate. Components are generally soldered onto the PCB to both electrically connect and mechanically fasten them to it.
A dye-sublimation printer is a computer printer which uses heat to transfer dye onto materials such as a plastic, card, paper, or fabric. The sublimation name was first applied because the dye was considered to make the transition between the solid and gas states without going through a liquid stage. This understanding of the process was later shown to be incorrect. There is some liquifying of the dye. Since then, the process is sometimes known as dye-diffusion, though this has not eliminated the original name. Many consumer and professional dye-sublimation printers are designed and used for producing photographic prints, ID cards, clothing, and more.
Flexography is a form of printing process which utilizes a flexible relief plate. It is essentially a modern version of letterpress which can be used for printing on almost any type of substrate, including plastic, metallic films, cellophane, and paper. It is widely used for printing on the non-porous substrates required for various types of food packaging.
Offset printing is a commonly used printing technique in which the inked image is transferred from a plate to a rubber blanket, then to the printing surface. When used in combination with the lithographic process, which is based on the repulsion of oil and water, the offset technique employs a flat (planographic) image carrier on which the image to be printed obtains ink from ink rollers, while the non-printing area attracts a water-based film, keeping the non-printing areas ink-free. The modern "web" process feeds a large reel of paper through a large press machine in several parts, typically for several metres, which then prints continuously as the paper is fed through.
Security printing is the field of the printing industry that deals with the printing of items such as banknotes, cheques, passports, tamper-evident labels, security tapes, product authentication, stock certificates, postage stamps and identity cards. The main goal of security printing is to prevent forgery, tampering, or counterfeiting. More recently many of the techniques used to protect these high-value documents have become more available to commercial printers whether they are using the more traditional offset and flexographic presses or the newer digital platforms. Businesses are protecting their lesser-value documents such as transcripts, coupons and prescription pads by incorporating some of the features listed below to ensure that they cannot be forged or that alteration of the data cannot occur undetected.
In offset printing, a spot color or solid color is any color generated by an ink that is printed using a single run, whereas a process color is produced by printing a series of dots of different colors.
Rotogravure is a type of intaglio printing process, which involves engraving the image onto an image carrier. In gravure printing, the image is engraved onto a cylinder because, like offset printing and flexography, it uses a rotary printing press.
Once a staple of newspaper photo features, the rotogravure process is still used for commercial printing of magazines, postcards, and corrugated (cardboard) and other product packaging.
Dot gain, or tonal value increase, is a phenomenon in offset lithography and some other forms of printing which causes printed material to look darker than intended. It is caused by halftone dots growing in area between the original printing film and the final printed result. In practice, this means that an image that has not been adjusted to account for dot gain will appear too dark when it is printed. Dot gain calculations are often an important part of a CMYK color model.
In the theory of photography, tone reproduction is the mapping of scene luminance and color to print reflectance or display luminance, with the aim of subjectively "properly" reproducing brightness and "brightness differences".
Microcontact printing is a form of soft lithography that uses the relief patterns on a master polydimethylsiloxane (PDMS) stamp to form patterns of self-assembled monolayers (SAMs) of ink on the surface of a substrate through conformal contact as in the case of nanotransfer printing (nTP). Its applications are wide-ranging including microelectronics, surface chemistry and cell biology.
Printed electronics is a set of printing methods used to create electrical devices on various substrates. Printing typically uses common printing equipment suitable for defining patterns on material, such as screen printing, flexography, gravure, offset lithography, and inkjet. By electronic industry standards, these are low cost processes. Electrically functional electronic or optical inks are deposited on the substrate, creating active or passive devices, such as thin film transistors; capacitors; coils; resistors. Printed electronics is expected to facilitate widespread, very low-cost, low-performance electronics for applications such as flexible displays, smart labels, decorative and animated posters, and active clothing that do not require high performance.
In printing and graphic arts, mixing of two dissimilar colors in two adjacent printed dots before they dry and absorb in substrate is referred to as color bleeding. Unless it is done for effect, color bleeding reduces print quality.
Industrial Digital Printers can be divided into a variety of different categories. As the industry becomes more mature, and the number of manufacturers increases, the line between the broad descriptions becomes less defined.
Ultrasonic nozzles are a type of spray nozzle that uses high frequency vibration produced by piezoelectric transducers acting upon the nozzle tip that will create capillary waves in a liquid film. Once the amplitude of the capillary waves reaches a critical height, they become too tall to support themselves and tiny droplets fall off the tip of each wave resulting in atomization.
The G7 Method is a printing procedure used for visually accurate color reproduction by putting emphasis on matching grayscale colorimetric measurements between processes. G7 stands for grayscale plus seven colors: the subtractive colors typically used in printing and the additive colors. The method is used in many applications of printing such as offset lithography, flexography, and gravure since it uses a one-dimensional neutral print density curve (NPDC) to match neutral tonality between two G7 calibrated printing systems. The G7 method is not a completely accurate color management system nor is it officially standardized by the International Color Consortium (ICC).
