NEW TO SCREEN PRINTING?

GLOSSARY OF TERMS YOU SHOULD KNOW

 
Abraders:
Products used to make small scratches on monofilament threads to help with emulsion adhesion.

Adobe Illustrator:
The original vector drawing and editing program for print and art layout.

Adobe Photoshop:
A digital pixel-based image editing program for print applications.

All Heads Down (press):
A manual press with the mechanical ability to print in registration in any and all positions simultaneously.

Angle (line or dot):
the direction printed dots point in relation to center or 0 on the 360 degree circular scale.

Actinic Light:
Light range in and near the ultraviolet spectrum where most photochemical reactions occur.

Bezier curve:
A curve defined by mathematical formulae (also see: vector).

Bitmap:
A data file that corresponds bit for bit with an image displayed on a screen (often confused with pixel and raster).

Bleeding:

  1. Visible migration of shirt colors into the printed ink layer;
  2. The wicking of ink from the edge of the design out into open areas on the substrate (also known as or used in relation to sublimation).

Block out:

  1. To apply a small patch to an open section of mesh on a stencil;
  2. Liquid air dry product used to fill holes in the stencil on a screen (also known as Screen filler)

Blow out (ink removal):
To remove a cured plastisol spot or stain with a powered spot removal gun.

Blowing agents:
see: puff additives

BMP (.bmp):
"Bitmap" is a standard file format characterized by the width and height of the image in pixels.

Break down:
The act of removing and cleaning the screens used in a print job.

Bridging:
Where emulsion stencil spans the gaps from thread to thread on mesh.

Butt register:
When the edges of printed colors come edge to edge but do not overlap.

Camera-ready (art):
see: Print ready (art).

Capillary films:
Pre-sensitized emulsion on a film base; named for the adhesion action.

Catalyst:
Ink additive used to aid in substrate bonding; mixed by weight; used for nylon and synthetics.

Chemical cure test:
The use of celosolve acetate or .99 ethyl acetate to test for a plastisol cure on a garment.

Centipoise:
A relative measurement of the viscosity of a liquid in standard units.

Chain Dot:
Elliptical dots known for joining at the ends from dot to dot, an undesirable optical effect known as string of pearls.

Choke:
Choking is a type of trap that reduces the size of the underlying color and covers it with one (or more) colors to trap the underlying color with an overlapping edge of the top color.

Coating trough:
see: scoop coater

Cold peel (transfer):
A plastisol transfer that is printed on a special paper backing designed to be removed from the garment only after the design is applied to the garment with a transfer heat press and allowed to cool to room temperature.

Combination film/stencils:
Pre-sensitized film and liquid emulsion combination on one screen.

Contamination:
When referring to spot and streak type emulsion flaws, this arises from damage-causing chemicals or particles.

Continuous tone:
A grayscale or color graphic with smooth ranges of tone like a photograph or shaded pencil drawing.

Corel Draw:
A vector drawing and editing program for print and art layout.

Cost:
The value of inputs used to produce products/services (variable/fixed).

Cristalina:
A small flake of reflective foil or plastic suspended in plastisol for printing as a specialty ink.

Cure:
The point where plastisol becomes a wash-durable product (320°).

D-Max:
Measure of the dark (art) areas on a film.

D-Min:
Measure of the transparent (clear) areas on a film.

DCS 2.0:
An EPSF Adobe Photoshop file format used for printing from Adobe Illustrator's separator.

Degreasing:
Washing screens with an industrial degreaser to prevent contamination.

Delamination:
A condition caused by underexposure in which the emulsion lifts away from the mesh.

Diazo emulsion:

  1. One of the three types of emulsions (other two are SBQ-photopolymer and dual care);
  2. Emulsion that uses benzene diazonium for light reactivity.

Diffusion dither:
Tonal changes made with small same-size squares in random patterns; similar to stippling (also known as stochastic dots).

Direct (liquid) emulsion:
A photo-reactive liquid chemical applied to screens used to create a stencil.

Dot gain:
A condition where printed dots enlarge from the desired or original size.

DPI:
"Dots Per Inch." Squares printed from a printer that makes lines, shapes, or dots.

Drying cabinet:
A sealed box-like storage device used to quickly remove moisture from screens.

Dry trap (flash printing):
To print over an underlay of gelled or dried ink, as compared to wet-trap or wet on wet printing.

Dual cure emulsions:

  1. One of the three types of emulsions (other two are SBQ-photopolymer and diazo);
  2. Emulsion that uses a hybrid of diazo and SBQ salts for light reactivity.

Durometer (Duro):
The measure of the hardness or stiffness of a flexible squeegee blade.

Dye migration:
When sublimated dye gasses trapped under the ink layer diffuse into the ink layer.

Dyed mesh:
Mesh fabric colored or tinted to help reduce light transmission.

Emulsion:
A photo-reactive chemical or film that is attached to a mesh and developed for use as a stencil.

Emulsion remover:
Used in the process of reclaiming screens, a chemical that will dissolve emulsions (also known as stencil remover or stripper).

E.O.M.:
"Emulsion Over Mesh." Measured percentage of emulsion past the threads in relation to the total thickness of mesh and emulsion.

EPS (.eps):
"Encapsulated Postscript" is a graphics files designed to be incorporated into other digital documents.

Exposure calculator:
A simple and easy test for finding the correct exposure time using a divided light filter with progressive UV exposure-blocking steps.

Exposure latitude:
The range of exposure time in between underexposure and overexposure (with any given emulsion) that will produce a useable stencil.

Exposure unit:
A device that emits UV light used to expose a screen and make a photo stencil.

Extenders:
A chemical added to plastisol used to smooth the texture; increase volume, reduce opacity, and will not reduce viscosity.

Extending frames:
Retensionable frames using square opposing bars that move out from the center to tighten mesh.

Face-side (screen):
The side of a screen that touches the substrate (shirt).

Face coating:
A second (or more) coat of emulsion over a dry first coating, applied to the emulsion on the substrate side of the screen.

Fibrillation:
A condition where small garment fibers break out of the ink layer when washed, creating a fuzzy look.

Fish eye:
A result when contamination on a screen causes the drying emulsion to form a circular thin spot.

Fixed costs:
Expenses whose total does not change in proportion to the activity of a business.

Flash additives:
Ink additives used to decrease flash time and smooth the gelled ink surface.

Flashing:
Applying heat to a substrate while on press to gel the top layer of ink.

Flood:
To fill the open stencil areas and mesh with ink before a print.

FM printing:
see: frequency modulation

Font:
A complete typeface of one size and family.

Four Color Process:
Color printing reproduction of an image using the specialty translucent colors cyan, magenta, yellow, and black (also known as CMYK).

Frame:
A modular dimensionally stable platform used to support mesh fabric.

Frequency:
The count of location lines for dot shapes per inch (LPI) for a halftone print.

Frequency modulation (FM printing):
This effect (also called stochastic) can be simulated using the bitmap conversion in Photoshop and choosing the diffusion dither option in each channel.

Frequency interference:
Moiré-like condition when the threads in mesh fabric cross small stencil openings.

Gel inks:
Clear, frosted, or tinted plastisol inks that when applied thickly have a bulbous wet look.

Gel point:
The temperature where plastisol forms a skin on the top layer of ink.

Ghost print:
A light visible image in a screen caused by former art or ink from earlier use of the screen.

Ghost remover:
A chemical used to break down or remove ink stains from mesh fabric without damage to the mesh threads (also known as ink and/or stain remover).

Ghosting:

  1. A result of chemicals in cured plastisol off-gassing into a stacked cotton shirt causing a bleach-like action;
  2. A transfer of reactive dyes in cotton or cotton-blend garments.

GIF (.gif):
"Graphics Interchange Format" is a standard image format (an open, nonproprietary format defined in 1987 by CompuServe).

GUI:
"Graphical User Interface" that uses pictures to help create computer input and output.

Halation:
Light scatter caused by a clear or empty area from the surface of the emulsion and the positive.

Halftone:
A grayscale image reproduced by varying size of same-color dots or a gray tone made of even dots in a pattern.

Halftone dots:
Rows of shapes in a print to simulate grayscale tones — made of variable size shapes (square, round, elliptical).

Haze removers:
One- or two-part chemicals used to remove faint ink stains or ghost images on mesh fabric.

HD (thread diameter):
Old designation for largest (thickest) thread in a mesh count range.

High-density inks:
Plastisol inks that hold the form and sharp edges of deep stencils after printing.

High opacity (HO):
An ink mixture with high amounts of pigments to raise the opacity level.

Hot split (transfer):
A plastisol transfer that is printed on a special paper backing designed to be removed from the garment immediately after the design is applied to the garment with a transfer heat press.

Imbedded particle:
Contaminates that get trapped when drying emulsion on screens.

Index:
The process of separations of butting opaque colors to create an illusion of secondary colors (see simulated process).

Indirect films:
Light-reactive, hand- or mechanically-cut light-masking material on a film base that is exposed/developed or cut/weeded before it is applied to a mesh as a stencil.

Ink degrader:
A chemical used before stencil breakdown to remove oily inks and cleaners, and to prevent staining.

Ink migration:
When substrate dyes change directly from the solid to the gaseous state (also known as bleeding or sublimation).

Ink-jet:
Printers that produce images by projecting electrically charged droplets of ink.

Ink volume:
The theoretical amount of ink that can be transferred by the stencil and mesh.

JPEG (.jpg):
"Joint Photographic Experts Group" is a standard compressed image format (that can have a downside of low quality).

Light integrator:
An electronic sensor (eye) that measures the volume of light energy and controls the exposure time.

Light undercutting:
A process where light passes at an angle past a positive (also known as undercutting).

Lock-in:
A condition where chemicals cause the emulsion to harden to the point where it cannot be reclaimed.

Low-bleed (LB):
An ink mixture with chemicals that help prevent color migration or bleeding.

LPI:
"Lines Per Inch." Printed lines of dots or shapes that form "halftone dots" for exposure.

Market share:
The percentage of the total available market or market segment that is being serviced by a company.

Masking film:
A dual layer film of clear plastic and a UV-blocking cut and weed top layer used to make positives (ie. Rubylith).

Mesh:
An open weave fabric attached to a frame used to create an attachment point for a stencil.

Mesh marks:
A condition resulting from low mesh counts and low emulsion thickness that can cause the printed ink layer to have visible impressions of the pattern of the mesh in the top surface.

Micro registration:
The movable hardware on a print head that lets the user make small adjustments in print alignment.

Micros:
see: micro registration

Moiré (pronounced more-ray):
A visual pattern made when dots cross on a printed product at wrong angles; can be caused by frequency interference of mesh angle.

Monofilament:
A strand or thread made of a solid flexible material.

Mottling:
A blotchy uneven print caused by lack of ink volume or substrate irregularities.

MSDS:
"Material Safety Data Sheets." Government-required forms for each and every chemical in a print shop.

Multi-durometer:
A squeegee blade that has a harder layer sandwiched next to or in between softer layers.

Multi-filament:
A strand or thread made up of twisted or woven smaller threads.

Numbering:
The process of printing or applying contrasting numbers onto garments for sport use (such as jerseys).

O.D.:
"Outside diameter" or "outside dimensions." Used to refer to the outer measurements of the screen frame.

Off-contact:
The distance or condition of the screen raised above the substrate.

On-contact:
The condition in which the screen is touching the substrate.

On-press wash:
A chemical used to clean ink from a screen that is compatible with the emulsion so the stencil can be used again.

Orange peel:
A condition resulting from ink sticking or stringing from the substrate to the mesh causing a rough texture.

OS:
"Operating System" is the user interface for the control of a computer.

Over-flood:
A condition where excess ink is forced past the mesh and stencil when flooding.

Overexposure:
A condition resulting from a stencil being exposed to excessive light, causing a loss of image quality.

Pallet:
The solid smooth surface used to hold a garment for printing (also known as platen).

Pallet (platen) adhesive:
A temporary pressure-sensitive glue used to keep textiles from moving while printing (also known as spray tack).

Pallet (platen) paper:
A large tape-like temporary covering for press platens.

Paper stencils:
Separate stencils made of paper or film aligned on shirts to print numbers.

Particle hole:
A small hole in exposed stencil caused by contaminates during exposure; is similar to a pinhole but of an irregular shape.

Patching:
Repairing screen mesh on the frame using flexible glue and scraps of mesh.

PDF (.pdf):
A file format for representing documents independent of application, hardware, operating system, or print device.

Photopolymer emulsions:

  • One of the three types of emulsions (other two are diazo and dual care);
  • Emulsion that uses styryl basolium quaternary (SBQ) salts for light reactivity (also see: SBQ).

Picking:
The act of lifting and moving a garment multiple times before printing.

PICT (.pct):
"Macintosh Picture" is a standard Macintosh image format.

Pigment concentrates:
Ink additives used to raise opacity, and for richer, more vivid colors.

Pinhole:
A small unintended hole in the stencil where ink can cause a small dot on the substrate.

Pixel:
Picture element; the smallest component of a digital image (also see: raster or bitmap).

Plain weave:
A fabric weave where thread crosses over or under each transverse thread.

Plastisol:
An ink that creates a tough washable print on garments.

Platen:
The solid smooth surface used to hold a garment for printing (also known as pallet).

Polyvinyl acetate:
PVAc-water-resistant polymers used in emulsions.

Polyvinyl alcohol:
PVOH-solvent-resistant polymers used in emulsions.

Popping:
The act of flipping garments fast enough or pulling garments under tension so that parts of the garment can flip into the wet ink

Positive:
Film, paper, or vellum with dark art areas used to make a photo stencil (also see: separations).

Postscript:
A powerful printer language implemented in 1982 by Adobe Systems.

Pricing objective:
What you want to accomplish with your pricing strategy (i.e. increase profit 10%).

Pricing strategy:
How you will accomplish your pricing objectives (i.e. reduce shirt cost by 5%).

Printable area:
The area where a screen can reasonably print an image without distortion.

Print Ready (art):
Art in a form ready to shoot on a screen (positive on film)

Process color:
A specially mixed set of translucent inks used to create multiple colors when printed on top of one another.

Profit:
Revenue left after cost is deducted (Profit = Revenue - Cost).

Profit margin:
Measure of profitability (Profit margin = Profit/Revenue).

"Proud of the mesh":
An old English screen printing term to describe anything past the peak of the knuckles of the mesh; is measured in a percentage of the total thickness of both mesh and emulsion, and referred to as the emulsion-over-mesh ratio.

Puff additives:
Ink additive used to cause microscopic "bubbles" to form in the ink; can increase viscosity and opacity .

Raster:
Scanning pattern of parallel lines forming an image on a screen (often confused with bitmap or pixel).

Reclaiming:
The act of applying chemicals to dissolve and remove an emulsion stencil after printing.

Reducers:
Chemicals used to lower the viscosity of inks.

Retensionable frames:
Frames that have built-in mesh-tensioning features.

Revenue:
The amount of money earned from activities, mostly from sales of products/services to customers.

RIP:
Raster Image Processing.

RGB:
"Red Green Blue" is a term to describe the type of color pallet used in a photo-editing program.

Roller frames:
Retensionable frames that use opposing rollers to tighten the mesh.

Rolling (mesh):
A condition where excessive pressure on mesh fabric forms a wave in front of the squeegee.

Rollover:
A condition where the flexible squeegee blade folds over so much as to flatten an edge against the mesh.

Rub test:
The use of a clean white cloth (both wet and dry) to test the possibility of sublimation, migration, and/or bleeding.

Rz value:
Stencil roughness measurement; lower Rz numbers are smoother.

S (thread diameter):
Old designation for smallest (thinnest) thread in a mesh count range.

Sawtoothing:
A stair-step pattern on the edges of a print.

SBQ:
"Styryl Basolium Quaternary" salt; used in photopolymer emulsions; a family of chemicals that are light reactive.

Scoop coater:
A long trough-like device used to apply liquid emulsion to screen mesh (often referred to as a coating trough).

Scorching:
A condition where chemicals in a textile fabric discolor due to excessive heat.

Screen:
The complete printing unit made of tightened mesh attached to a stable frame.

Screen printing:
The act of printing with a screen, stencil, and squeegee onto a substrate.

Scumming:
A result of underexposure that causes a slimy back layer of emulsion to move into open stencil areas.

Separations (Seps):
The positive images used to block UV light in an exposure to create a photo stencil.

Serigraphy:
Distinguishes artistic from commercial screen printing (Latin "seri" [silk]; Greek "graphein" [to write]).

Shoot:
see: exposure

Simulated process:

  1. A process where multiple opaque colors are used to create a realistic image on dark substrates;
  2. Using specific spot colors to approximate multiple visual colors — a process that simulates continuous tone images and from a reasonable viewing distance can seem photorealistic.

Smearing:
Color moved out of position by screen movement or by an excess volume of ink.

Snap-off:
The action of the mesh where it lifts off the substrate after the squeegee passes.

Soft-hand extenders:
Ink additive used to raise print ink volume in higher mesh counts; will lower opacity.

Solvents:
Chemicals that thin or reduce oil-based products.

Spot color:
A term used to describe separations or printing using specific colors.

Spray tack:
see: pallet adhesive

Squeegee:
The flexible blade and handle that transfers ink past the mesh and stencil onto the substrate.

Squeegee-side (screen):
The side of a screen where the ink is welled and the squeegee touches the screen.

Stencil removers:
see: emulsion remover

Step coating test:
A process where multiple thicknesses of emulsion are applied to one screen for testing.

Step test (wedge):
A simple and easy test for finding the correct exposure time by using a timed and sectioned progressive exposure using a light safe cover.

Stippling:
An artistic technique of using small, somewhat randomly placed same-size dots to simulate varying degrees of grey or shades of a color.

Stochastic dots:
Same size shapes in random patterns with variable density (also see: diffusion dither).

Streak:
A trail in a dried unexposed screen caused by travel of contamination.

Stretch additives:
Ink additives that build stretching qualities; for lycra or neoprene.

Stretch test:
A test where the ink layer on textiles is stretched to check for a cure — the test can only indicate an under-cure.

Stringing:
Tracks in an image caused by plastisol dragged behind the squeegee blade.

Stripper:
see: emulsion remover

Sublimation:
When substrate dyes change directly from the solid to the gaseous state (also see: ink migration or bleeding).

Substrate:
The product to be printed.

Suede inks:
Plastisol inks that take on the texture of suede when cured.

T (thread diameter):
Old designation for medium thread diameter in a mesh count range.

Thickeners:
Ink additive used to build ink viscosity, raise opacity level, and increase tackiness.

Thixotropic:
Becoming fluid when stirred and returns to a semisolid state upon standing.

Thread growth:
A condition caused by overexposure that makes emulsion travel into open areas around the threads of the mesh; such exposed emulsion forms sleeves over the threads.

TIFF (.tif):
"Tagged Image File Format" is a standard image format.

Tonal (tonal-range) compression:
A condition where highlights and dark tones lose visual clarity, because of dot gain and lack of contrast from dot to dot.

Toner:
A powdery ink made of magnetic attractants used in a laser printer to develop a xerographic-fused image to paper.

TPI:
"Threads Per Inch." The count of thread in one inch of mesh fabric.

Transfer (printed):
A printed product that is heated under pressure to move an image onto the substrate.

Transfer paper:
A special paper used to print heat transfers (printed in reverse).

Trap registration:
Separations where the edges of the colors overlap one another.

Twill weave:
A fabric weave where threads will cross two or more transverse threads.

Typeface:
A particular style and design of alphanumeric characters and symbols. (example: Times Roman, see related: Font)

Under base:
see: underlay

Undercutting:
A process where light passes at an angle past a positive (sometimes referred to as light undercutting).

Underexposure:
When photo emulsion is not exposed to UV light long enough to be hardened; presents several adverse effects throughout the screen printing process.

Underlay:
A first layer of plastisol gelled and used as a support for later top colors to gain opacity.

Variable costs (direct costs):
Expenses that change in direct proportion to the activity of a business.

Vector (art):
The representation of separate shapes and text with mathematically set outlines.

Vellum:
A semi-transparent paper product used in laser printers to produce positives (produces an inferior product).

Warp:

  1. The direction from end to end (length) as a mesh fabric exits the weaving machine;
  2. The direction of feed into a machine.

Wash test:
Testing a cure by cutting a print in half and washing one half several times to make a comparison.

Washout:
The development of a stencil after exposure with water.

Weeding:
The act of removing unwanted top layer material from vinyl or masking film.

Weft (Woof):

  1. The direction from side to side (width) as a mesh fabric exits the weaving machine;
  2. The width of the bolt.

Wet trap (Wet on wet print):
To print ink on top of a previously printed ink while the first underlay or under-base ink is wet.

Wicking:
A process when ink is drawn into the threads of a printed fabric or paper and enlarges from its original size.