Rr

rack
a series of usually flat platforms of open construction stacked or hinged one over the other on which printed sheets may be placed for air drying at ambient temperature.

rack drying
the air drying of screen printed sheets in racks, usually at ambient temperatures, but can also be dried in a room where temperatures are elevated.

racking
the placing, manually, of screen printed sheets on racks for drying.

rad
(1) a unit of energy absorbed from ionizing radiation, equal to 100 ergs (10^-5 joules) per gram of radiated material, also referred to as megarad; (2) abbreviation for radiation.

radiant energy
a form of energy consisting of the electromagnetic spectrum that travels at 299,792 kilometers (186,206 miles) through vacuum, reducing speed in denser media such as air and water.

radiant tube
a steel tube of alloy or ceramic composition where fuel is burned for supplying radiant heat to a lehr or kiln.

radiation
ultraviolet or infrared wavelengths of light and heat energy used for curing an ink film or exposing a photostencil.

radical
an extremely reactive chemical particle with an atom or group of atoms with at least one unpaired electron, also reffered to as free radical.

radio frequency welding
a method of joining thermoplastic using radio frequency field to apply the necessary heat.

radiometer
an instrument, usually self contained, for measuring UV energy inside of a curing unit.

radius
(1) a line segment joining the center of a circle with any point on its circumference; (2) a measure of the curve or range on which a printing screen travels in printing tapered objects; (3) measure of the curve on which artwork is distorted to fit a curved or tapered surface of a bottle or cylindrical object.

radius printing
the technique of screen printing on conical shapes, where the printing screen moves along the arc of a circle while the squeegee remains stationary.

rag content
paper made wholly or partially from cotton fibers thatmay be derived from reclaiming fabrics or virgin cotton. (Rag papers may contain from about 25% to 100% fibers).

rag paper
refer to rag content.

ragged
a type of composition set where lines of type do not start or end at the same position; lines of type centered in a column.

raglan
a type of sleeve sewn with seams slanting outward from the neck to underarm.

railroad bond
a heavy-duty signage board ranging in caliper from 0.457 to 0.610 mm. (018 to .024 inches).

rainlap
the various sheets of an outdoor poster are laid-out and printed so that when posted, the bottom edge of the top sheet will overlap the top edge of the bottom sheets.

raised printing
refer to thermography.

RAM
acroynm for random access memory.

ramp
a registration lug, protrusion, or cavity that is molded into a container or jar; refer to ACL lug.

random access memory (RAM)
the high speed portion of computer memory that is stored on special chips for use in current applications or procedures.

range
a measure of dispersion equal to the difference or interval between the smallest and the largest set of quantities.

rapid tensioning
a method of stretching mesh to optimum tension in one or two steps.

raster
the process of rendering an image or page, pixel by pixel, in a sweeping horizontal motion, one line after another.

raster image
an image that is defined as a collection of pixels arranged in a rectangular array.

raster image file format (RIFF)
a storage format used with gray scale images.

raster image processing (RIP)
a process using mathematical algorithums to enlarge and print an image.

rasterization
changing vector type image information to raster image information.

rasterized type
type that has rough or stair-stepped edges.

rattle
a sound made by paper that is shaken for an indication of stiffness or dryness.

raw materials
the components necessary to the manufacture of a product. (Basic items or materials in a chemical composition; basic items or materials used in constructing a mechanical device).

raw umber
an inorganic pigment with excellent fade resistance, excellent fade resistance, good resistance to acids and alkali, resists bleeding, poor gloss.

rayon
a synthetic textile fiber made from regenerated cellulose (wood pulp), cotton linters, or other vegetable matter.

r-chart
refer to trend chart.

RCRA
acronym for the Resource Conservation and Recovery Act of 1976 (US).

reactive dilutent
monomer or mixture of monomers used to reduce the viscosity of a UV ink.

reactive dye
dye that works by forming a chemical bond between the fiber and the solution where heat is used to develop the proper shade, used to make fabric colorfast.

reactive material
a chemical substance or mixture that will actively polymerize, decompose, condense, or become self-reactive under conditions of shock, pressure, or temperature.

reactivity
the ability of a substance to change by combining with another substance or breaking down.

reactor
UV curable unit consisting of UV lamps, reflectors, cooling system, and shielding.

read color
markings that are created in an ink that can be read by an ORC device.

ream
a quantity of 500 sheets of paper, formerly 480 sheets or sometimes 516 sheets (printer’s ream).

ream marker
a small piece of paper inserted in a quantity of sheets to mark off reams.

rear adhesive
the mounting adhesive for a membrane switch normally 0.002 to 0.005 thick.

receding color
a color that appears to move away or create the illusion of distance such as blue, green, and violet.

receptivity
able to receive.

receiver sheet
the piece of a two part diffusion transfer material that is not sensitive to light.

reciprocity effect
the extent to which time/light intensity ratios affect exposure.

reciprocity law
photographic rule stating that exposure is a function of the product of both exposure time and light intensity, not of either variable alone.

reclaimed screen
printing screen reconditioned for use by removal of excess ink and stencil from the mesh.

reclaiming
(1) the process of removing both ink and stencil from the screen mesh after a printing; (2) the process of cleaning used solvent to obtain a reusable product.

reclaiming fixer
refer to silver recovery.

reclaiming solution
a chemical used to remove a screen printing film or emulsion from screen mesh to make the mesh useful again.

recommended tension
the optimum tightness of a screen mesh as determined by the mesh manufacturer.

recording density
the number of bits of data recorded per linear inch on magnetic media.

recovery
in stretched materials, the difference between ultimate elongation and dead stretch; a return to normal condition.

recto
the right-hand page of a book, cover, or sheet; the odd numbered pages.

recycle
to restore waste or spent material to a reusable condition.

red
one of the three additive primary colors of light.

red iron oxide
an inorganic pigment with excellent fade resistance, good hiding ability, good resistance to acid and alkali, resists bleeding, poor gloss.

red label
the color and type of label required by the Department of Transportation (DOT) on shipment of flammable materials (US).

red lake C
a warm, bright red pigment used in printing inks.

red lead
an orange red oxide of lead similar to orange mineral, formally used in printing ink.

red 28
an organic pigment with fair transparency, good bleed resistance, fair to good lightfastness, and poor resistance to acid and alkali.

reducer
a solvent or other additive used for lowering the viscosity and tack of an ink formulation.

reducing atmosphere
a furnance environment that tends to remove oxygen from a substance or material placed in a lehr or kiln.

reducing flame
a rich flame or fire resulting from a mixture containing too much fuel or too little air for proper combustion.

reduction
(1) the amount of, or the act of, thinning an ink with a compatible solvent; (2) a decreased size or area of an original copy, made photographically in a camera, or manually by pantograph, or dividers.

reference colors
familiar colors, such as blue sky, green grass, and human skin tone, often referred to when evaluating process color reproduction.

reference edge
the area on a data medium used to establish specifications or measurements in or on the data carrier.

reference state
the position of a fabric in relaxed condition after five washings.

reflectance
the ratio between the amount of light reflected from a given tone area and the amount of light reflected from a white area.

reflectance, specular
mirror-like reflectance. The magnitude of the specular reflectance on glossy materials depends on the angle and on the scattering of the light by an uneven surface.

reflectance, total
reflectance of radiant flux reflected at all angles from the surface, thus including both diffuse and specular reflectances.

reflection
the direction change of a ray of light when it falls on a surface and is thrown back into the medium from which it approched.

reflection densitometer
an instrument that measures the amount of incident light received from the surface of a substrate; also refer to densitometer, reflection.

reflection diffused
parallel incident rays that are reflected at various angles from a rough surface.

replection specular
parallel incident rays that are reflected at a constant angle from a smooth surface.

reflective art
artwork either line or halftone that is rendered on an opaque surface.

reflective copy
illustrative copy that is viewed by light reflected from its surface.

reflective ink
ink containing microscopic glass spheres that have the capability of returning light rays to the observer.

reflective sheeting
sheet material with one face treated with a substance, usually microscopic glass spheres that return light rays striking it.

reflectivity
the capacity of a surface to reflect light rays.

reflex blue
a strong organic blue pigment with the highest tinctorial strength of any blue pigment; also referred to as alkali blue.

reflex copy
the exposure of a photosensitive film by passing light through the back of the film, then through a positive or negative, and reflecting the light back from the support surface.

reflex paper
a light sensitive material for contacting same size reproductions.

refractive index
the deviation of light as it passes through a given substance, given as the ratio of its velocity in a vacuum to its velocity within the substance.

refractometer
an instrument for measuring idices of refraction.

refractory
a material that has a relatively high melting temperature and is capable of enduring continuous high temperature.

register
(1) to precisely align either manually or automatically one print color to another; (2) a mark on a design that identifies it as having been offically recorded with the US Patent Office.

register bond
a common lightweight writing paper designed for single and multicopy business forms.

register check
a mylar roll material that is coated with a light adhesive used to determine registration without printing a actual production sheet or part.

register device
a mechanical device used to align a design elements prior to or during printing.

register guide
physical stops, usually three in number, placed on the printing base in relation to two adjacent edges of the printing sheet to ensure proper positioning for printing; also called feed guides.

register locking system
a mechanical system where a printing screen and its printing base can be locked into position after adjustment to accomplish register.

register mark
a crosshair or othertarget image applied to original copy as an aid for positioning and aligning purposes.

register punch
a device used to cut holes in film flats to ensure registration.

registered numbers
heat-applied numbers that are centered on a transfer sheet of paper with precision.

registrar
a company that conducts quality system assestments to recognized quality system standards or set of requirements.

registration
refer to register.

registration lug
refer to ramp.

registration pin
a spring loaded finger inside a chuck that locates the ramp or lug and stops rotation at the registration point.

regression analysis
models the relationship between one or more independent variables and a dependant variable.

regrind
excess or waste material in a thermoplastic molding process that can be reground and mixed with virgin raw material.

relative humidity
the amount of water vapor present in the atmosphere expressed as a percentage of the maximum that could be present at the same temperature.

relative mesh strength
a calculation of a specific cross section area of the threads.

relative sensitivity
the degree that a photographic emulsion is affected by light.

relative viscosity
the ratio of the absolute viscosity of the solution to the absolute viscosity of the pure solvent.

relaxation
the release of tension within the stretched screen mesh after a given period of time.

relaxation shrinkage
the shrinkage that occurs during the first laundering of a garment, due to the relaxing of tensions applied during fabric manufacture.

release
(1) the act of freeing or separating a decal from its backing or release liner; (2) the force required to accomplish the separation.

release agent
a lubricant used to coat a mold cavity to prevent the molded part from sticking to the mold; also referred to as parting agent.

release and adhesion tester
instrument used to measure adhesion values of pressure sensitive paper stock by recording the force required to strip away face material or label stock from the release liner at preset speed and angle.

release coat
the treated coating of the release liner that permits pressure sensitive label to release from the liner.

release coat transfer
a defect where the release coat adheres to pressure sensitive adhesive, detaching from the release liner during transfer.

release liner (backing sheet)(liner)
an extremely smooth paper on one side usually treated with a silicone used as a carrier for the pressure sensitive label stock, and serves as a protectant for the adhesive prior to application.

relief printing
a printing process where the print image area is raised above the non-image area such as flexography and letterpress printing.

remake
(1) to make anew; (2) to repeat for a better end result.

removability
the force required or the condition under which a pressure sensitive decal can be removed from a substrate.

removable adhesive
a pressure sensitive adhesive characterized by low adhesion properties allowing removal from a substrate or surface.

repeatability
(1) capacity for near-exact duplication of a former result; (2) continuous duplication of an image within a given tolerance.

repellency
the ability of a fabric to resist wetting and staining.

replenisher
a chemical solution that extends the life of a developer and/or fixer solution.

reproduction
the multiple, identical duplication of an original.

reproduction copy
finished, camera ready art; also refer to camera ready art.

reproductive toxins
chemical substances that affect reproductive ability including chromosome damage (mutation) and effects on fetuses (teratogenesis).

reprographics
a method of copying used by architects and engineers to create blueprints.

reprography
A term originating in 1963 for the arts and sciences of copying and duplicating print quantities below commercial printing levels.

re-run
to redo a portion of or all of a job due to error or defect.

resampling
changing the resolution of a bitmap file without altering its physical size.

rescreen
halftone negative or positive made from a printed halftone usually with a diffusion filter placed in front of the camera lens to eliminate moiré patterns.

reservoir
(1) a unit on a press designed to hold and supply ink; (2) the blocked out area between one end or side of a screen printing stencil and the adjacent frame, where ink to be printed is held for pickup by the squeegee.

residual shrinkage
the percentage of shrinkage remaining in a garment after being pre-shrunk.

residual tack
the tackiness remaining in a film which, although set, does not reach the tack-free stage.

resiliency
ability to regain quickly an original shape after being strained or distorted.

resin
(1) any of a number of clear to translucent yellow or brown solid or semi-solid substances of plant origin as copal rosin and amber used in lacquer varnish ink, adhesive, and synthetic plastic; (2) in printing ink, the material that binds the pigment to the substrate.

resist
a plate coating that hardens over the non-image areas after exposure to light; mixed with bichromated gum or other coating solution protects non-image areas during etching.

resistance
the opposition a material offers to direct current flow, measured in ohms.

resistance, insulator
the ratio of an applied voltage to the total current carried by a specific insulating material.

resistance temperature characteristics
relationship between thermistor resistance and the temperature it is sensing.

resistor
a device, material, or component that offers opposition to the flow of an electric current.

resist printing (textile)
the printing of a resist agent on the cloth to prevent a printed ink from affecting a preselected protected area.

resite
a thermosetting resin at the C-stage, or final stage of processing, where it becomes insoluble, or cured.

resitol
an uncured thermosetting resin at the B-stage, or intermediate stage of processing.

resol
a thermosetting resin in its solvent-soluble stage.

resolution
(1) a measure of image sharpness or the performance of an optical system, expressed in lines per millimeter or lines per inch; (2) the smallest distance that can be measured by an istrument.

resolution target
any test image that measures the resolving power (ability to produce fine detail) of a printing system.

resolving power
the relative ability of a lens or emulsion to accurately reproduce fine detail.

Resource Conservation and Recovery Act of 1976 — RCRA (US)
a federal hazardous waste, solid waste, and waste reduction program involving remedial investigations, feasibility studies, and implementation of corrective measures.

retarder
an additive for ink that slows down drying time; a solvent with slower evaporation characteristics.

retensionable frame
a screen printing frame or chase with a built-in means of tensioning applied mesh.

reticulation
(1) a separation or cracking of a photographic emulsion caused by processing at too high temperature or thermal shock in transferring from a very warm bath to one that is too cold; (2) a defect where the ink film recedes in large areas due to incompatibility of the surface energy of ink and substrate.

retouching
the act of altering continuous tone prints, halftone negatives, or positives to eliminate defects, emphasize detail, or perform minor color corrections.

retrofit
the addition or removal of equipment, or a required adjustment, connection, or disconnection of an existing piece of equipment to comply with a change.

retro-reflective
the property of a material that causes it to reflect light back toward the source under non-daylight conditions.

return-blade
refer to flood bar.

reverse
an image that is the opposite of the original.

reverse printing
(1) process of printing on the second surface of a material, referred to as back printing; (2) forming an image by laying ink down around the subject and letting the white space show through to form the image.

reverse roll coating
a coating technique where the coating is pre-metered between rolls then wiped off the substrate, usually by a doctor blade, coating thickness is controlled by the metering gap and the speed of the rolls.

reversing turntable
a geared motor that reverses its motion automatically.

rewash
glassware that is washed due to misprint or mis-spray.

rewetting
(1) the re-softening of a dried ink film; (2) the ability of fresh ink to unblock dried ink in a mesh.

rewinder
a device for rerolling a substrate after printing.

rework
a salvage operation to recover defective work.

Reynold’s number
the ratio of a liquid’s inertial forces to its drag forces (flow rate and specific gravity are inertia forces, while pipe diameter and viscosity are drag forces).

RF
acroynm for radio frequency.

RFI
acroynm for radio frequency interference.

RGB
a color model using red, green, and blue, the additive primary colors used by video display.

RH
abbreviation for relative humidity.

rheogram
a graph of flow curves plotted by shear stress versus shear rate that provides a picture of a material’s response to varying shear rates, yield, stress, and thixotropy.

rheology
the science of flow and deformation of fluid matter under pressure: the study of flow characteristics of liquids.

reheology modifier
alters the flow characteristics of an ink.

rheopectic
the opposite of thixotropic, sometimes referred to as anti-thixotropic, a characteristic associated with some resins.

rhodamine red
a class of clean organic bluish red pigments with excellent light fastness, good resistance to acid, poor resistance to alkali, often called magenta when used in color process screen printing inks.

rich flame
refer to reducing flame.

ridging
a swelling of the outer layers of a roll material, usually due to moisture absorption.

RIFF
acroynm for raster image file format.

right-reading
copy that reads correctly (same as original) from the emulsion side.

rigid
inflexible; not bending.

rigid board
a fully cured laminate, generally over 0.030 inch thickness, used in manufacturing double-sided printed circuit boards.

rigid frame
a screen frame made of metal or wood where the mesh is tensioned and then glued to the frame.

rigid PVC
polyvinyl chloride or polyvinyl chloride/acetate with a relatively high degree of hardness or resistance to bending or flexing.

rigidsol
a plastisol having a high modulus of elasticity.

ring-spun yarn
twisted strands of natural or synthetic material produced on ring-frame equipment, (a finer yarn than open-end yarn).

ringer
a t-shirt usually white bodied with contrasting ribbed neck and sleeve bands.

RIP
acroynm for raster image processing.

ripple finish
an irregular paper finish of undulations or waves formed by an embossing process.

risk
a relative term, referring to the expected probability of adverse effects from exposure to a substance or process.

rm
abbreviation for ream.

robotics
a mechanical computer controlled apparatus that resembles a human being and is capable of performing human task; the act of using robots.

robot, industrial
a programmable, multifunctional machine designed to perform specific, repetitive tasks.

Rockwell hardness number
number derived from the net increase in depth of impression as the load on a penetrator (steel ball or diamond cone) is increased from a fixed minimum load to a higher load and then returned to minimum load.

roll fed
a printing press or converting machine that recieves substrate as a continuous web.

roll label
pressure sensitive labels that are packaged in continuous roll form.

roll out
ink spread on a surface by hand roller or brayer for testing purposes.

roll-to-roll
refer to web fed.

roller coater (roll coater)
a machine designed for solidly coating sheet material by means of a series of rubber or steel rollers.

roller frame
a screen frame where the side members roll to tension the mesh.

roller rim punting
a method of applying color to the rim of an item with a neoprene or steel roller.

roomlight film
silver based photographic material that can be handled under yellow safelight, tungsten, or fluorescent lighting conditions.

room temperature curing adhesive
adhesive that sets within an hour at room temperatures from 21º to 30ºC (68º to 86ºF) and reach full strength without heating.

rope & groove
a screen stretching method that involves a wooden frame where the mesh is held in place by a rope pushed into a deep groove; no longer used in the industry.

rosette
a pattern formed when halftone color images are printed in register at the correct angle; a sub-image element in four color process that resembles the symmetrical shape of a rose.

rosin
a natural soft resin obtained after removing turpentine from the sap of a southern pine tree.

rosin oil
an oil obtained from the destructive distillation of rosin.

rotary load
refers to one design of a garment printing device whereby the loading pallet/platen rotates around a central shaft.

rotary screen printing
the screen printing of roll to roll (web) materials using a semi-rigid cylindrical metal screen that revolves on its axis with a squeegee blade mounted inside the print cylinder.

rotational register
registration of a work piece by rotating either the printing screen or the printing base on its center.

rotational viscometry
a method for measuring the viscosity of a material by sensing the torque required to rotate an immersed spindle at constant speed, where the torque is proportional to the viscous drag on the spindle, and thus to the fluid viscosity.

rotogravure printing
refer to gavure printing.

rough art (sketch)
a sketch or drawing that shows relationship of design elements, in unfinished form.

roughening
a treatment for abrading the smooth surface of the strands of monofilament screen printing mesh, for better adhesion of a stencil film.

round corner cutter
a specialized device used for cutting rounded corners on square-edged substrates.

Royal
a tradename for a paper size of 483 x 610 mm (19 x 24 inches).

rpm
aabbreviation for revolutions per minute.

rub fastness
refer to abrasion resistance.

rub test
refer to abrasion test.

rubber
an elastomer, sometimes used to manufacture squeegee blades.

rubber cement
a liquid adhesive composed of rubber dispersed in an organic solvent.

rubber solvent
a petroleum naphtha with an evaporation rate that is slower than textile spirits, but faster than lactol spirits used in rubber cement, rubber type adhesives,lacquers, intaglio and printing ink.

rubine
an organic reddish pigment.

rubine red
organic pigment with fair transparency, good bleed resistance, poor lightfastness, and poor alkali resistance.

rubometer
an instrument used for measureing the abrasion or scuff resistance of a print.

Rubylith®
a thin red or amber light safe masking film coated on a polyester backing; a trademark of the Ulano Corporation.

rule
(1)a line used to delineate, separate or emphasize copy; (2) a steel blade used in making a die for diecutting.

Rule 66
The original US air quality control regulation enacted by Los Angeles County in California for the purpose of eliminating smog caused by petrochemical degradation of some organic solvents.

run
refer to printing run.

run chart
refer to trend chart.

runners
channels in a mold where the molten or liquid plastic flows into the mold to fill the cavaity.

running
(1) the action of a thin viscosity ink spreading beyond the point where originally applied; (2) a condition of the color forming tear droplets during the firing cycle.

running stitch
a stitch primarily used for welding, outlining, and quickly covering space between separate design elements in embroidiery; also called walking stitch.

run-off
any rainwater, leachate, or other liquid that drains over land from any part of a facility.

Back to Top