Inkjet printing glossary of terms
These commonly used words and terminology are often used in product descriptions of inkjet ink and inkjet technology. Some of the words are unique to the inkjet industry, while others are common to any printing method.
The erosion or wear of a surface from thermal or mechanical stress. In thermal inkjet printing (TIJ) the rapid and frequent collapse of heated microbubbles creates wear of the chamber and reduces the effective work-life.
The sharpness of image, text, or graphics in printing. Generally, low acuity can be seen more prominently in images produced with lower-resolution printheads.
The ability to control the placement of individual droplets. Sometimes expressed as dots per inch or centimeter.
A unit of length equal to one hundred-millionth of a centimeter, 10−10 meters, used mainly to express wavelengths, such as UV and LED curing lights.
While not quantifiable, the term describes the relative ability of the printed images to retain their color or blackness over time.
Individual ink jets aligned or grouped.
Visible or invisible barcodes or other machine-readable images.
Ink pigment particles join or cement together creating larger particles. The effect is lower ink dispersion and can also cause clogging of the printhead nozzle.
An ink solution using water as the carrier. It is also known as water-based ink.
An ultraviolet (UV) light source using an excited mercury vapor to create the wavelength.
A drop-on-demand printhead where all drops ejected by the printhead are of the same volume.
Drop-on-demand (DOD) inkjet technology that rapidly boils the ink to create a bubble that is ejected as a drop. Also called Thermal Inkjet (TIJ).
The point at which surface tension causes an ink droplet to pinch off from a continuous ink stream relative to the voltage phase of the inkjet printhead.
Is caused when inkjet ink spreads or diffuses on or into other inks or the substrate. It is often considered a defect because it reduces image acuity. The term can also refer to eliminating air from the chamber of a continuous inkjet printer (CIJ) or from the ink delivery system of a piezo printhead inkjet printer.
Covering the inkjet printhead when idle to avoid damage, ink evaporation or unintended curing from a light source.
The base solution of the ink into which dyes, pigments, and other additives are combined.
The part of a continuous inkjet printer that captures unwanted droplets before reaching the printing surface. These intercepted droplets are generally recirculated into the ink reservoir.
The creation and collapse of bubbles from heating that raise the vapor saturation pressure within a continuous inkjet module resulting in erosion of printhead surfaces.
The cavity area directly behind the orifice plate in an impulse printhead in Piezo technology. It is called a manifold in continuous inkjet systems.
The components of one unit of a printhead, which include the piezoelectric transducer, restrictor, associated chamber, and orifice plate.
The acronym for continuous inkjet, which is one of two broad types of inkjet technology. The other being drop on demand (DOD).
The electrodes in a CIJ printer that create an electrical field that controls the trajectory of the droplets to the substrate or the recirculation system.
The letters refer to cyan, magenta, yellow and black inks used for producing process colors.
The recombining of satellite and main ink droplets in the air before reaching the printing surface.
The wrinkling of paper from too much liquid is applied, usually when water-based ink applied to a small area.
The build-up of ink particulates on the surface of a thermal inkjet chamber caused by the heating of the ink.
The range of colors that can be produced using CMYK (four-color) printing.
The dye or pigments used to produce the ink color.
The chamber plate or orifice plate.
The measurement of viscosity used to determine a liquid’s ability to resist flow. The viscosity of ink can vary based on environmental and mechanical influences.
The increase or decrease of ink droplet velocity in a channel caused by the firing of adjacent channels.
The nozzle density or channels per inch.
The temperature point that piezoelectric inks lose their magnetism.
The time that inkjet nozzles can be uncovered and idle before requiring wiping or purging.
The electrical component that charges continuous inkjet droplets causing them to be recirculated rather than striking the printing surface.
Removing dissolved air in ink to avoid bubbles forming in the printheads that can cause nozzle failures.
A process that can print any image at varying quantities limited only by its data system and its resolution limits.
The failure of ink to be expelled because of air trapped in the chamber.
The distribution of ink components, such as pigments, throughout the solution.
Also known as screening or halftoning, it is the representation of a share using a pattern of dots that appears to be solid.
Drop-on-Demand. It is the printhead technology that uses electromechanical valves to release ink onto the printing surface.
A measurement of the spread of a droplet of ink on a substrate before it cures or dries.
Dots Per Inch which is a measurement of addressability of an inkjet printer.
The electrical signal applied to the print module actuator or heater to expel the ink from the chamber.
Droplet production rate
The maximum droplets of ink produced by an orifice, chamber or print system expressed in droplets per second.
Drop placement accuracy
The accuracy of drops landed on the printing surface, which is dependent on jet alignment, distance, and drop velocity.
The volume in picolitres (pL) of a drop from the printhead.
The speed of an ink droplet ejected from the print nozzle.
The time required for ink to dry to the touch after application to the substrate.
The time a printing system is operating compared to idle time.
The time nozzles can be uncovered and idle before performance printhead is reduced.
A soluble ink colorant in the base solution.
A DOD printhead with ink fired from nozzles on the edge of the printhead, perpendicular to the action of the heater or actuator.
Ink that is cured with high-energy electrons rather and no photoinitiators.
A printhead with the actuator diaphragm or heater parallel to the nozzle plate.
The description of the resistance to degradation of printing by various environmental factors: water-fastness, wash-fastness, rub-fastness, and light-fastness.
The number of drops ejected from a nozzle per second. Related: Drop Velocity, Drop Size.
An arrangement of printheads that cover the width of a substrate with the printing surface passing under the printheads. The printheads are stationary.
The spread of ink often caused by the capillary action of the fibers of the substrate.
The process or event causing the ejection of the droplet.
The coagulation of particles in an ink solution, which can be reversed through shaking. Agglomeration, while similar, is irreversible.
A fluid used for cleaning inkjet printing systems or the process of cleaning a system.
Air bubbles created from dissolved gas being released in ink when agitated.
Ink that meets strict government regulations for printing directly on food packaging products.
A DOD printhead technology that ejects different sized drops to improve print quality.
In a thermal inkjet printhead the mechanism that boils the ink, creating pressure that expels the ink from the nozzle.
Hot melt ink
Often these are wax-based Inks that are solid at room temperature and liquid when heat is applied. These inks don’t penetrate the substrate surface, making them less rub-fast.
A subjective, non-quantifiable assessment of the printed image.
Technology that relies on pressure to expel the ink from the nozzle. Piezo-based systems create pressure through a crystal that changes the pressure of the ink in the chamber. Thermal systems rapidly boil the ink to create bubbles.
The control system that receives ink from the supply tank and distributes it to individual chambers or orifices.
Delivers the ink to the printhead at the right temperature and pressure.
The fluid property relationship of the liquid to a solid surface. Also called the “wetting” property, it is the measure of the contact angle between the liquid and surface.
Interlaced, interdigitated, interlocked
The overlapping alignment of rows of orifices, often on a scanning printer that creates an image using multiple printing passes.
The variance in an ejected ink drop perpendicular to the nozzle plate.
Deposit of decomposed ink on heater components of thermal inkjet technology.
A stream of ink discharged from an orifice into free space.
The measurement of energy required to expel a droplet of ink.
The time nozzles can be uncovered and idle before performance printhead is reduced.
The Light Emitting Diode emits a wavelength for curing inkjet ink.
The tail of ink that follows the droplet after nozzle ejection.
The rate a substrate passes under printheads.
Large Ink Supply System using bottles or vats.
The curvature of the ink at the printhead nozzle caused by the difference in pressure from the outside air and nozzle.
A magnetic mechanism that changes the shape of ferromagnetic fluids to expel the ink.
A continuous inkjet technology that delivers ink droplets to multiple positions on the substrate.
One color printing, often black and white.
Uneven ink density or uneven color quality caused by inaccurate dot placement or varying dot density.
Printing with more than one highlight or spot color and black, but not process (CMYK) printing.
The hole from which the ink is ejected. It is also called an orifice.
The spacing between orifices in a printhead.
The flat surface into which the nozzles are fabricated.
Optical density (OD)
The measure of how strongly ink absorbs light.
Inkjet printing technology that uses crystals to that change dimension by electrical stimulation and allowing ink to be expelled from the nozzle. (Dimatix | Konica Minolta | Kyocera | Panasonic | Ricoh | SII | Xaar | X-BAR)
An ink colorant that is suspended and insoluble in the solution.
See hot-melt ink
The initiating process of running ink through a print head to expel air from the chamber or manifold.
Partially curing an ink with LED lamp.
The distance from the bottom of the printhead to the substrate. It is also called the throw distance or print gap.
The inkjet component containing a single or multiple channels that eject ink droplets.
Print to cure time
The time for a droplet to fully cure after striking the substrate.
The liquid ink that accumulates on the exit side of the nozzle plate. In excess, the puddle can prevent ink from leaving the nozzles.
Clean or flush ink through the system to clean out debris or air.
Lead zirconium titanate is the crystal mainly used in PIJ technology.
The process of capturing and reusing ink in continuous inkjet systems.
Controls the flow of ink from the printhead manifold to the chambers.
A dimensionless number that plays a prominent role in understanding the patterns of a fluid’s behavior related to viscosity and inertia.
An unwanted ink droplet produced behind the main drop during the break-off, which either merges with the main drop (fast satellite) or drifts away from the main drop (slow satellite) deposited on a different place on the printing surface.
An electronic component on each printhead to control the voltage to the transducers.
The method of causing a PIJ device to bend rather than changing length or volume.
A liquid used as the carrier in solvent ink.
Applying energy to CIJ streams to produce a uniform ink stream.
A defect caused by a non-aligned print head characterized by a dark line or gap from overlapping printing. Also, the joining of two print sections to create a single image.
Stirring ink in the chamber with a low amplitude pulse without ejecting droplets.
The printing surface. Read more about printing on different substrates.
Substrate force restraining an ink droplet into the minimum surface area possible.
See print distance.
Equipment that converts one type of energy into another. For piezo crystals, electrical energy is converted to mechanical energy in the form of motion that controls the ink flow.
Titanium dioxide often used for white pigment.
Ultraviolet light radiation causes a chemical reaction of polymerization to change the ink from a liquid to a solid.
A low-cost, low-resolution DOD technology using micro-electromechanical valves to spray large block images such as text or characters on cartons.
The physical property of liquids to resist flow or shear.
Volatile Organic Compound (VOC)
A carbon compound, excluding carbon monoxide, carbon dioxide, carbonic acid, metallic carbides or carbonates, and ammonium carbonate, that easily becomes vaporous or gaseous that participates in atmospheric photochemical reactions and are potentially hazardous. VOCs are often used as quick-dry solvents.
The spreading of ink on a printing surface, determined by surface tension and surface energy.
Explore the various types of inks and technology at Kao Collins.