Hh

h
symbol in metric system for hecto

hairline register
very tight register of color to color or dot to dot with a standard tolerance that is within one-half row of dots.

hairlines
fine lines appearing in fired enamel on glass, ceramic ware, or on the surface of drying organic inks or coatings.

halation
(1) blurring or spreading of light on a photographic positive or negative, diffusing image detail; (2) the scattering of exposing light rays reflected off screen mesh threads, thereby affecting resolution of the stencil image.

halftone
a reproduction of continuous tone artwork such as a photograph through a crossline or contact screen or by digital generation that converts the image into dots of various sizes.

halftone dot count
refer to halftone line count.

halftone dot resolution
the ability of a printing screen to accurately reproduce a halftone dot of a specific shape and size.

halftone line count
the number of rows of dots per centimeter or per inch, used as a means of determining the fineness or coarseness of a halftone screen, negative, positive, or stencil. (The halftone dots, regardless of size, are equidistant from each other on their centers, thus, located in parallel lines.)

halftone negative
a film negative on which the halftone dots form the image corresponding to the original continuous tone art.

halftone positive
a film positive made by exposing film through a halftone negative or positive acting film to obtain the dot structure.

halftone printing
a technique where an image that has been broken up photographically into a structure of tiny dots, each equidistant from others on centers, but varying in size in relation to light and dark areas, can be printed to preserve the gradations of tone.

halftone reproductions
printed matter produced by using halftone photomechanical techniques.

halftone screen
(1) a sheet of glass or film that is used as an intermediate between continuous tone copy and photographic material; also refer to contact screen, crossline screen, and levy screen; (2) printing screen containing a halftone dot pattern.

halftone tint
an area printed with all halftone dots of the same percentage to provide an even tone or color; also refer to screen tint.

halide
a binary compound formed by the direct union of halogen with a more electropositive element or radical.

halo
(1) shadowy image around a screen print caused by movement of the stencil mesh under squeegee pressure; (2) hazy area around a fired glass decoration; (3) enlarged highlight dots (fringe); (4) a bright line tracing the edge of an image, usually an anomaly of excessive digital processing to sharpen or compress an image.

halogen
any of the elements astatine, chlorine, bromine, and fluorine that form a salt by direct union with a metal.

hammock
a cradle for holding ampules and vials during firing.

hand
refer to feel.

hand-cut stencil
a printing screen utilizing a hand cut film for the stencil; also refer to knife cut film.

hand fed
designates manual feeding of a screen printing press or unit.

handle
the touch and sound produced when paper is handled.

handmade paper
paper having rough or deckle edge, where the mold is dipped into a vat and is lifted forming the sheet; refer to deckle edge.

hand processing
(1) manual screen printing; (2) the processing of camera film in trays by hand.

hand table
see hand unit.

hand unit (hand machine, manual unit)
a screen printing device operated entirely by hand, including feeding stock, lowering the screen frame, flooding the screen, printing, raising the screen frame and removing the stock.

hang tag
identifying card attached to any garment.

hansa yellow
a pigment with good flow properties and better lightfastness than diarylide yellow.

hard colors
a range of glass colors especially formulated for extreme hardness and resistance to alkali attack; requires high temperature firing.

hard copy
(1) a printed document on paper; (2) a printout that accurately represents an electronic file.

hard glass enamels
a range of high temperature firing glass enamels especially formulated for extreme hardness and resistance to alkali and acid.

hardener
(1) a chemical treatment used on a water soluble screen printing stencil to make it impervious to water; (2) chemical which promotes curing or hardening of a thermosetting resin used interchangeably with curing agent.

harding on
a heat treatment not in excess of 600ºC (1112ºF) that fires organic colorant on ceramic ware.

hardness
(1) degree of solidity of an imprint with relation to impact resistance, chemical resistance, and resistance to marking or deterioration by mechanical stress; (2) the degree of gloss appearance of a fired glass enamel decoration; (3) resistance of a plastic or rubber material to indentation; refer to Shore hardness.

hard sized
paper that has been sized to allow for a greater degree of water resistance.

hard squeegee
a squeegee with a very stiff blade.

hardness, Shore
refer to Shore hardness.

hatch test
a crosshatch ink adhesion test, refer to ASTIM D3359 (US).

hazard
any dangerous condition that interrupts or interferes with a normal process.

Hazardous Communication Standard (HCS)
a US standard administered by the Occupational Saftety and Heath Administration (OSHA) that requires employers to advise their employees about health hazards in the workplace and to train them in safe handling of hazardous substances; also referred to as the "Right-to-Know Law."

Hazardous Materials Identification System (HMIS)
a rating system developed by the US National Paint and Coatings Association (NPCA) to identify the level of three hazards encountered in the workplace health, reactivity, and flammability by numbers from 0 to 4 with 0 being the least, and with letters used to designate personal protective equipment necessary for handling the material.

hazardous material list
identified substances that constitute a clear and imminent danger to life, or pose an unreasonable risk to health, safety, and property, when transported in commerce.

hazardous waste discharge
the accidental or intentional spilling, leaking, pumping, pouring, emitting, emptying, or dumping of hazardous waste into or on any land or waters.

hazardous waste generation
the act or process of producing a hazardous waste.

haze
(1) residue of ink and/or stencil material remaining in a screen following stencil removal; (2) undesired cloudiness found in transparent areas of film, or base substrate.

HCS
acroynm for Hazardous Communication Standard (US).

HD
one of four common designations for monofilament screen mesh (thread thickness); acroynm for heavy duty.

HDCP
acroynm for high definition color printing.

HDPE
acroynm for high-density polyethylene.

heat activation
the application of heat to convert an adhesive coating from a dry state to one where adhesion can be accomplished.

heat curing
(1) the subjection of a printed textile substrate to steam heat to set the dyes and drive off volatiles; (2) the application of dry heat for predetermined interval to dive off volatiles and speed drying and in some instances to harden the printed film on the substrate.

heat distortion point
(1) the temperature that a material softens enough to distort under a given load; (2) the temperature at which a standard test bar deflects 0-25 mm (0.010 in) under stated load of either 0.45 mPa (66 psi) or 1.82 mPa (264 psi).

heat forming
refer to thermoforming.

heat lamp drying
the drying of a screen print with heat lamps.

heat resistance
the property of a material that inhibits physical or chemical changes caused by exposure to elevated temperature.

heat sealing
uniting two distinct surfaces by fusion, either of the coatings or of the base materials, under controlled conditions of temperature, pressure, and time (dwell).

heat seal machine
specially engineered equipment for applying heat transfers to a variety og substrates; also refer to heat transfer press.

heat sink
any device that absorbs and draws off heat from a hot object.

heat transfer
the flow of heat by conduction, convection, or radiation.

heat transfer application
the transfer of a printed image from a carrier to a receiving substrate by the use of heat and pressure.

heat transfer, nylon
thermal transfer produced utilizing a special screen ink designed especially for adhesion to nylon substrates.

heat transfer, screen flex
thermal transfer made from any type of artwork and in as many colors as desired, using plastisol ink.

heat transfer paper
a special paper that releases the ink printed on it, when heat and pressure are applied over time.

heat tunnel
a heated device that shrinks plastic wrap to tightly conform to the material being wrapped.

heavy bodied ink
an ink of high viscosity or stiff consistency.

heavy metal
toxic metallic elements contained in some pigmented materials such as chromium, cadmium, and lead.

heavyweight
fabric heavier than 10 ounces per linear yard; equal to 1.60 yield. (Standard weight in the industry is 8 ounces, 2.0 yield or lighter).

hecto (h)
a prefix utilized in the metric system of measurement that denotes 10 to the power of two (10²) or 100.

hemp
a coarse, durable, strong, soft, woody fiber obtained from the inner bark of the hemp plant.

hemp, industrial
a fiber used in clothing that is softer, more breathable, and durable than cotton.

HEPA filter
a cleanroom high efficiency particulate air filter for filtering 0.3 micron particulates and larger.

hermetic
totally sealed against the escape or entry of air; air tight.

Hertz (Hz)
a scale used for measuring the number of cycles per second; a unit of frequency of a periodic process equal to one cycle per second and a metric unit of measure of frequency.

HEW
acroynm for health, education, welfare.

Hexachrome
a color separation process developed by Pantone™ that uses six instead of four process colors.

HF
acroynm for hydrofluoric.

hf
abbreviation for high frequency.

HFC
acroymn for hydrofluorocarbons.

hickey
an imperfection in a print or coating that appears as a small solid area surrounded by a white halo or as an unprinted spot surrounded by printing ink.

hide glue
a glue made from animal hides and used as a blockout and in preparation of resist stencils.

hiding power
(1) opacity; the relative ability of a coating material to hide or obscure a surface to which it has been uniformly applied; (2) the contrast ratio of a gallon of ink or a pound of pigment.

HiFi color
an alternative printing process that extends the capabilities of printing devices. This system uses stochastic screening, 6-color printing, and other techniques to expand the possible color gamut well beyond that of traditional 4-color processes.

high contrast film
a litho film that develops out to either black or to a transparent area with no intermediate gray.

high density polyethylene (HDPE)
a thermoplastic made from hydrogen and carbon atoms combined in the ethylene monomer C₄H₄.

high definition color printing (HDCP)
a specialized color printing process that uses balanced dot frequency and screen rulings as fine as 625 lpi to reproduce near-photographic quality images.

high fire
the firing of ceramic ware at or above 1200ºC (2200ºF).

high-energy dye
sublimation dye that requires relatively high transfer temperatures usually over 204û C (400û F). As a result they offer excellent permanence and wash-fastness.

high gloss
a type of surface having extreme smoothness and excellent light reflecting qualities.

high impact polystyrene (HIPS)
a thermoplastic made by blending standard polystyrene with impact improving resins.

high key image
an image that is mostly white.

high performance plastic
plastic that is suitable for use above 175ºC (347ºF).

highlight
the lightest or whitest areas of an original copy or reproduction.

highlight density
the density of a halftone negative or positive that ultimately result in the printing of the highlight area.

highlight dot
the largest dot in the film negative or the smallest dot in the film positive.

highlight end
the portion of the halftone positive or the printing screen that prints the highlight areas of a halftone illustration.

highlight exposure
refer to main exposure.

high mesh count
finer mesh materials for screen printing specifically those above 120 threads/cm (300 threads/inch).

high mesh tension
mesh made from a specially formulated polyester that aises optimal tension from 42 N/cm to 120N/cm.

high tack
highly aggressive adhesion.

high temperature adhesive
bonding agent that will enable a pressure sensitive label to adhere when applied to a surface that has an elevated temperature.

high tolerance printing
reproduction that relies on precise dimensions and placement of design elements.

hinge
a strip of cloth or other flexible material used as a connector to attach two moveable parts of a display.

hinge clamp
a special hinge with provisions for clamping that is attached permanently to the printing frame.

HIPS
acroynm for high-impact polystyrene.

histrogram
graphical representation of a pattern of variation that exists in a particular process measure usually depicted by vertical bars drawn to indicate frequency levels of data collected within specific ranges.

HLS
acroynm for hue luminance saturation; a color model based on these three coordinates of color.

HMIS
acroynm for Hazardous Materials Identification System.

hp
abbreviation for horse power.

hoarding
a British and Australian term for a billboard.

holdout
the property of a substrate to resist or retard penetration of ink.

hold-down
a device used to secure a lined garment or jacket to the platen of a textile press.

holding power
the time required for a given weight to peel a given amount of pressure sensitive tape or material from a vertical panel.

holography
a photographic system that uses laser light to expose film to a pattern developed by the interference pattern of the laser and the reflection, when viewed under specific conditions a 3D image is visible.

homogeneous
a substance that is uniform throughout its composition.

homogenizer
a high pressure ink mixer.

homopolymer
a polymer produced from a single type of monomer.

hook (rotary hook)
a circular device that spins around the bobbin case with a pointed arm protruding from its body.

hook and rivet
a hook attached by a rivet.

hook-in hook
a stamping that can be pressed into the back of a display.

hook-in pocket
a pocket construction that permits choice of placement, attached without hole insertion.

hook lock
a device for connecting display parts.

hoop
two concentric rings used to stabilize the fabric in the area of the material to be embroidered.

horizontal camera
a process camera so constructed that the copy board and camera head are in vertical parallel positions, one or both moving horizontally on a bed for focusing and adjustments.

horizontal resolution
the number of vertical lines that a system is capable of producing (counted on a horizontal axis).

horn easel
an easel for pushing out the upper part of a display.

horsepower (hp)
a standard unit of power measurement in the US equal to 33,000 foot-pounds per minute or the force.

hot air motor
a rotary motor actuated by hot air rising through vanes.

hot color
a ceramic or vitreous color dispersed in a thermoplastic composition that is solid at room temperature, but liquid when heated.

hot embossing
embossing with heated rolls or plates.

hot melt ink
(1) ink that is melted to the proper printing consistency by using an electrically heated screen; (2) a form of inkjet printing using thermal material that solidifies very quickly on paper and exhibits excellent dot shape, contrast edge definition, and holdout characteristics.

hot paint
thermoplastic glass enamels used in the glass decorating industry.

hot peel
screen printed heat transfer that is designed to have the release paper removed immediately after application, while the transfer ink is still hot.

hot pressing
the curing of thermoset adhesive by heat and pressure, as in the production of a multilayer printed circuit board.

hot spot
an area where light for exposing film is not properly diffused or is too far from the film during exposure concentrating its intensity in an area causing overexposure.

hot spot diffuser
a light shield attached to a carbon arc lamp to eliminate hot spots in lighting.

hot stamping
a method of printing that uses a hot metal die to impress an image onto the surface of a substrate.

hot wax screen
a printing screen with metal frames and mesh that can be electrically heated for printing thermosetting inks.

hr
abbreviation for hour.

HSB
acroynm for hue staturation brightness; a color model based on these three coordinates of color.

HSV
acroynm for hue saturation value.

ht
abbreviation for height.

hue
(1) one of the the attributes of color; an object defined by its angular position in a cylindrical color space or on a color wheel; (2) the actual name for a color.

hue error
a measure of color deviation from theoretically perfect subtractive process color, expressed as a percentage.

humectant
an additive used to promote moisture retention in an ink; such as glycerin used to retard the drying of a water-based ink.

humidistat
an instrument that indicates or controls the relative humidity of the air.

humidity, absolute
refer to absolute humidity.

humidity, relative
refer to relative humidity.

humidity control
a means of regulating the amount of moisture in air by drawing it through a condenser type unit that removes excess moisture, discharging the dried air for recirculation, or conversely adds water vapor to a given atmosphere.

hunch back easel
an easel positioning and supporting the protruding part or parts of a display.

hybrid circuit
a thick film screen printed circuit made by attaching active components to the passive thick film printed pattern; may be a single-layer, or multilayer, where at least two conductive layers are separated by dielectrics.

hybrid imaging
electronic imaging system that mixes traditional silver halide technologies with digital image technology.

hydraulic press
(1) a laminating press used in mounting where very heavy pressures are generated; (2) a screen printing press that oprtates by use of a pressurized fluid.

hydraulic pressure
the force that pushes the ink into the open image areas of the mesh, controlled by the pressure of the squeegee blade and the speed that it moves across the printing screen.

hydrocarbon
a family of chemical compounds consisting of carbon and hydrogen atoms in three general classes according to molecule structure: straight chain or aliphatic; ring or aromatic; and cyclic.

hydrofluoric acid
an aqueous solution of hydrogen fluoride (HF) used in etching and frosting glass.

hydrogen-ion concentration
the massing of hydrogen ions (more properly hydronium ions HO+) existing in an aqueous solution that is a measure of the active acidity or basicity. (The hydrogen ion concentration of a solution is usually expressed in terms of pH that is defined as the negative logarithm (to base 10) of the hydrogen-ion concentration).

hydrogen peroxide
(1) a chemical used as a hardener/developer in diluted form for many indirect photostencils; (2) a chemical used to remove scorching from some fabrics.

hydrometer
an instrument used for measuring the specific gravity of liquids.

hydrophilic
having a strong attraction for water; the ability to unite or dissolve in water.

hydrophobic
having no affinity for water.

hydroquinone
a white crystalline compound (C₆H₄(OH)₂ chemical used in some developer formulas.

hydroxyl
chemical group consisting of one hydrogen atom plus one oxygen atom.

hyg
abbreviation for hygroscopic.

hygro-expansivity
the change in the dimensions of a sheet of paper stock due to a change in ambient relative humidity.

hygrometer (hydroscope)
an instrument for measuring changes in atmospheric humidity.

hygroscope
an instrument used to measure the moisture content of a pile of paper relative to the humidity in the pressroom.

hygroscopic
the quality to absorb or release atmospheric moisture.

hypo
an abbreviation for sodium thiosulphate or sodium hyposulfite, a chemical used to fix the image on photographic film after it has been developed.

hysteresis
(1) the difference in the moisture content of a paper as indicated by its ascending and descending curves for relative humidity; (2) the difference in output when a pressure valve is first approached with increasing pressure, and then with decreasing pressure.

Hz
abbreviation for Hertz.

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