| The number of individually addressable points in a given area of print, usually expressed in DPIxDPI |
| Joining together of pigment particles to make larger particles |
| An ink using water as the main carrier |
| A form of continuous inkjet technology where the drops are either printed or recirculated |
| A drop-on-demand printhead where all drops ejected by the printhead are of the same volume (as opposed to a greyscale printhead) |
| A drop on demand technology where the ink is boiled very rapidly to grow a bubble and eject a drop. Also known as Thermal Inkjet (TIJ) |
| Covering the printhead when not in use to protect from damage, solvent evaporation and UV light |
| Continuous Inkjet, one of the two broad types of inkjet technology, the other being drop on demand (DOD), or impulse inkjet |
| Cyan, Magenta, Yellow and blacK process colours used to form full colour images. If a separate black ink is not used, then the black formed using just the three colours is referred to as a composite black |
| The material (dye or pigment) used to give colour to the ink and the final print, due to selective absorption or reflection of different wavelengths of light |
| The range of colours that can be reproduced with a process colour ink set |
| A method of ensuring correct colours are reproduced in the print |
| One of the two broad types of inkjet technology, the other being drop on demand (DOD), or impulse inkjet |
| Centipoise, the unit of viscosity |
| Channels Per Inch, equivalent to nozzle density (NPI) |
| The temperature at which the piezoelectric behaviour of piezoelectric material is completely lost |
| The representation of a grey level using a pattern of dots which, from a distance, gives an appearance equivalent to the average coverage of the dots (also known as screening or halftoning) |
| The time that nozzles can be uncovered and idle before they will no longer print (and need to be recovered by purging) |
| Removal of dissolved air from the ink to avoid bubbles forming in the printheads |
| Drop-On-Demand, one of the two broad classes of inkjet technology, the other being continuous inkjet (CIJ) |
| The size of a dot due to the spreading (wetting) of the ink on the substrate, relative to the size of the drop if no spreading had occurred |
| The diameter of a printed dot on the substrate |
| Dots Per Inch, a measure of the addressability (resolution) of an inkjet printer |
| The key characteristic voltage amplitude of the drive waveform |
| The accuracy with which drops can be landed onto the substrate, dependent on jet straightness and throw distance |
| The volume, in pL (picolitres) of the drop ejected from the printhead |
| See latency time |
| A colourant that is soluble in the ink |
| Drop on demand printer where the drops are fired from nozzles on the edge of the printhead, perpendicular to the action of the bubble or actuator |
| Printhead where the actuator diaphragm or heater is parallel to the nozzle plate |
| The resistance to degradation of a printed image by water (water-fastness), abrasion (rub-fastness) and UV light (lightfastness) |
| The number of drops ejected from a nozzle per second |
| A printing configuration where an array of printheads cover the whole width of the substrate to be printed, giving high speed printing with no movement of the printheads |
| (n) A compatible fluid used for cleaning ink systems and printheads. (v) Cleaning ink systems and printheads |
| Forming of air bubbles in the ink when agitated, caused by dissolved gas |
| An ink used to deposit a material with a specific application function, rather than to print colour |
| A drop-on-demand printhead capable of ejecting drops of different sizes, used to provide improved print quality (as opposed to a binary printhead) |
| A set of data that characterises a colour input or output device, or a colour space, according to International Color Consortium standards |
| A qualitative, subjective assessment of the printed image |
| Building up an image using multiple printing passes in a pattern designed to disguise the effect of missing nozzles |
| The angle at which a drop is ejected from the nozzle |
| Deposition of decomposed ink onto the heating elements in TIJ |
| The time that nozzles can be left uncovered and idle before there is a significant reduction in performance, for instance a reduction in drop velocity that will noticeably affect the image quality |
| Light emitting diode, a compact solid state UV source |
| A 'tail' of ink that follows the main drop once it has formed |
| The interface between the ink and the outside air at the nozzle, curved because of the pressure difference between the ink and atmospheric pressure |
| The (negative) pressure difference between the ink and atmospheric pressure |
| A type of piezo printhead design where the walls surrounding the ink channels are active and flex to create the necessary pressure wave for drop ejection |
| A form of continuous inkjet where drops can be deflected to multiple positions on the substrate |
| The spacing between nozzles in a printhead, normally given in nozzles per inch (NPI) |
| Nozzles Per Inch |
| Optical density (or absorbance) - a measure of how strongly a printed ink absorbs light |
| Original Equipment Manufacturer, a company that makes a product but sells it via someone else, normally without the manufacturing company's name |
| See decap time |
| The small opening in the printhead from which the ink is ejected |
| A type of ink which is solid at room temperature. The ink is heated in the printhead so it becomes a liquid, and on contact with the substrate it freezes to a solid |
| A material exhibiting the piezoelectric effect, where mechanical distortion of the material results in the formation of a charge across the material, or vice versa. The most common material in general use is Lead Zirconium Titanate (PZT) |
| A colourant that is insoluble in the ink, forming discrete particles |
| Use of a small UV lamp to partially cure a UV cure ink and fix the drops in place, prior to full curing |
| An actuator configuration where the piezo material is expanded and contracted along its length, resulting in a displacement along its length |
| Picolitre, or 1 million millionth of a litre (10-12 L) |
| Point Of Purchase, the place where goods are sold, used to refer to graphical advertising |
| Point Of Sale, the place where goods are sold, used to refer to graphical advertising |
| Pages Per Minute, the print speed, normally for A4 or US letter-sized sheets |
| Parts Per Million, concentration of a component in a solution |
| Print Quality |
| Component of the inkjet system containing an array of nozzles able to eject small drops of ink |
| A quantitative, objective measure of dot and line characteristics and other factors in the printed image |
| The time between the drop landing on the surface and it being fully cured |
| System where colours are reproduced by combining dots of CMYK or an alternative set of colours |
| Pumping ink through the printhead to remove air bubbles or dirt and recover inoperative nozzles |
| Lead (Plumbium) Zirconium Titanate |
| An actuator configuration where the piezo material deflects a diaphragm in the roof of a chamber which is perpendicular to the nozzle plate |
| Printheads and ink systems that allow ink to be circulated continuously past the nozzles, improving reliability |
| The ability of a printer to reproduce fine detail. In common usage this is taken to be equivalent to addressability, but high addressability will only equate to high resolution if the printed dots size are of suitable size and placed sufficiently accurately |
| Raster Image Processing software, which takes an image file input and produces a colour profiled, screened, bitmap output for the printheads |
| An unwanted drop produced behind the main drop, which either merges with the main drop (fast satellite) or drifts away from the main drop (slow satellite) |
| Printing modes which involve printheads being moved over the substrate (or the substrate under the printheads) to print in a series of swathes |
| The representation of a grey level using a pattern of dots which, from a distance, gives an appearance equivalent to the average coverage of the dots (also known as spatial dithering) |
| The rate of change of flow velocity with distance in a fluid |
| See fixed array |
| Small Office, Home Office markets, which for the printer market implies directly connected, rather than networked printers |
| Phase change ink |
| An organic liquid (or water) used as the main component in a solvent ink, in which the other components are dissolved |
| Ejecting ink from the nozzles when not being used for printing, to maintain fresh ink at the nozzle |
| Colours are produced using specific coloured inks, rather than from combining coloured dots |
| The joining of print swathes to give a complete print |
| The material being printed on |
| Surface force restraining a liquid, normally measured in dynes/cm2 (SI unit N/m). Equivalently the amount of work required to create a unit of surface area |
| The strip of print produced by a single scan of a scanning system |
| A drop on demand technology where the ink is heated rapidly to grow a bubble and eject a drop. Also referred to as ‘bubble’ inkjet |
| The distance between the printhead and the substrate, or the distance travelled by an ink drop |
| Thermal Inkjet, see above |
| Titanium dioxide, a commonly used white pigment |
| A tubular piezo element surrounding an ink channel where squeezing the tube creates the necessary pressure wave to eject a drop |
| Ultraviolet (radiation) |
| A process in which an ink undergoes a chemical reaction of polymerisation (and change of the state from liquid to solid) when exposed to UV radiation |
| The property of materials that exhibit both viscous and elastic characteristics when undergoing deformation |
| Measure of the resistance of a fluid to shear or tensile stress (flow) |
| Volatile Organic Compound, part of an ink formulation that is volatile and potentially hazardous |
| The electrical signal applied to the printhead piezo or heater to eject a drop of ink |
| The spreading of ink on a substrate determined by the ink surface tension and the substrate surface energy |
| Removal of excess ink and dirt from the printhead nozzle plate |
