Screen-printing Defined

From beginning artwork stages to the final end product, screen-printing is complex progress. We understand that customers may not understand all the terms we use in our production. To better understand our lingo, here is a compiled list of definitions that will help give you basic knowledge of what we mean when we say “vectorized artwork”, as well as, how reclaiming and burning screens makes your apparel come to life.

Artwork: Common term for an image or text that will be used for printing.

Automatic Press: A screen printing press in which the printing and the operation of the machine is accomplished through the use of electric servos and hydraulics. An automatic screen printing press has a much higher production rate than a manual press and will typically produce a higher quality print result.

Blockout: An emulsion like chemical that is used to cover pin holes and to block out any area of the screen that you do not want ink to pass through.

BMP – BMP (short for bitmap) is a graphic format used internally by the Microsoft® Windows®graphics subsystem and used commonly as a simple graphics file format on that platform. BMP files are usually not compressed and are typically much larger than compressed image file formats such as JPEG or PNG. Despite some shortcomings, the simplicity of BMP and widespread use in Microsoft® Windows® and elsewhere (as well as the fact that this format is well-documented and free of patents) make it a very common format. As such, many image programs are likely able to read in BMP files.

Burn: To expose an emulsion coated screen to a light source to create a stencil.

Coating: The process of applying direct emulsion to a screen.

Conveyor Dryer:   A belt dryer used for curing inks.

 

Cure: The process of using heat to completely fuse plastisol ink. Technically incorrect term for “drying” ink.

Dark Garment–  Shirts darker in color such as black, royal, green, red, etc.

Darkroom: A room devoid of light used for the purpose of drying screens coated with emulsion or capillary film.

Degrease: The process of washing a screen with a cleaning solution to remove all traces of dirt and oils prior to coating with emulsion.

Dehaze: using a caustic cleaning agent to remove ghosted images from a screen.

Dehumidifier– Used to remove water vapor in the area. Making a dry environment for screen preparation.

Discharge inks – used to print lighter colors onto dark background fabrics, they work by removing the dye in the garment leaving a much softer texture. They can be tinted with color pigments but exact colors are difficult to control.

Dots per inch (DPI) is a measure of spatial printing or video dot density, in particular the number of individual dots that can be placed in a line within the span of 1 inch (2.54 cm).

Durometer: unit of measurement used to describe the “hardness” of rubber. In screen printing, durometer relates to the “hardness” of a squeegee blade.

Emulsion: Photosensitive chemical in either liquid, roll or sheet form that is applied to a screen and used for the purpose of making a stencil.

Enamel:  A high gloss multi-purpose ink designed for long term outdoor application.

Exposure: Exposing an emulsion coated screen to light to create a stencil. Also known as “burning” a screen.

Film: A light sensitive material, used to create a stencil, that when applied to a screen with water adheres to the mesh by capillary action.

Flash Cure: To partially cure a print by subjecting the print to a heat source for a short amount of time.

Flash Cure Unit: An infrared heating element that is typically attached to a rotary turntable, positioned above the platen and used for the purpose of bringing a print to a partially cured state so a second print stroke can be applied to achieve desired opacity. A flash cure unit can also be used to completely cure a print.

Four-Color Process: Also known as CMYK or Full Color Process. A printing technique utilizing four ink colors (Cyan, Yellow, Magenta and Black) to print the entire color spectrum.

Full Cure: A state in which the plastisol ink film has completely fused, typically when a temperature of 320 degrees has been reached.

Glitter/Shimmer – metallic flakes are suspended in the ink base to create this sparkle effect. Usually available in gold or silver but can be mixed to make most colors.

Gradient: The representation of halftones dots from 100% to 0%

Halftone: A color or grayscale image that has been converted into a series of large and small dots.

Halftone Dot Types: Shapes of halftone dots. An elliptical dot is the ideal dot shape for screen printing. Round, square and diamond shaped dots are also used.

Halftone Line Count: Number of lines per inch (LPI) also known as line or screen frequency. The lower the LPI, the larger the halftone dots will be. Common halftone line counts for garment screen printing is a range from 35 LPI to 65 LPI.

Hand: How a print feels when touched. A print is commonly described as having a soft hand or a rough hand.

Infrared: Specific energy wavelengths which produce heat. IR radiation is typically used to develop the heat in a heating element of a flash cure unit or electrical textile dryer.

Ink: Common term used to describe the printable substance that is used to make a print. In the textile printing business, the most widely used ink is plastisol.

JPEG– This term stands for Joint Photographic Experts Group. It is the name of the committee that developed the format. A JPEG is a compressed image file format. The JPEG format is best for compressing photographic images. If you see a large colorful image on the Web, it is most likely a JPEG file. However JPEGS are NOT VECTORIZED Artwork.

Light Garment: White or pastel colored garments

Line Art: Black and White artwork consisting of no halftones or color.

Manual Press: Press used for transfer ink to a substrate manually.

Mesh: Woven material that makes up the printable portion of the screen.

Mesh Count: The number of threads in one square inch of screen fabric, measured in both directions. The lower the number, the coarser the mesh and the larger the screen opening.

Micro-registration: a mechanical adjustment on the print head of a screen printing press used for precise movement and alignment when lining up or adjusting a print job.

Off-contact: A method of screen printing of having a slight gap between the screen and the substrate for improved printability.

Opacity: An ink’s ability to cover the underlying color of the substrate.

Overexposed: Exposing a screen for too long of a period of time resulting in a screen that will be difficult or impossible wash out.

Platen Adhesive: Adhesive in either spray or liquid form that is used to hold down garment on shirt board when printing.

Platen Mask: A paper based tape that is applied to a shirt board (platen) for protection.

Pantone : A set of standard colors for printing, each of which is  specified by a single number.

Pinholes: Unwanted tiny specs that appear in the stencil after exposure.

Plastisol: A screen printing ink primarily for textile printing composed of the following components: PVC (polyvinyl chloride), color pigments, and plasticizers.

PMS : Pantone Matching System a system for mixing various inks to achieve the specified color as determined by Pantone.

Positive: Also known as film or film positive.  Any media used to completely block out UV light in the design area during the exposure process.

Pre-Press: All processes performed prior to actual printing.

Print-Flash-Print (PFP): Screen printing technique used to achieve an opaque print result by printing, flash curing the print and then applying another print stroke.

Print Side: The side of the screen that touches the substrate being printed on.

Proof: A computer generated mock-up to represent how the design will be printed with detailed specs.

Puff Ink: A special effect type of plastisol ink that “raises up” or expands dimensionally during the curing process.

Reclaim: To remove old emulsion from a screen so the screen can be reused.

Registration: The process of lining up the screen image to the original art and/or separations on a printing press and/or exposure unit.

Registration Mark: “Crosshair” target marks used for aligning a screen image to the source art.

Retensionable Frames: Special frames that allow the mesh to be applied over the screen without the use of adhesives or stretching equipment. The mesh is drawn tightly over the frame using either a roller or telescopic tightening system.

Safelight: A light that should be used when working with photosensitive materials like emulsion or capillary films to prevent accidental exposure to ultraviolet light. A yellow “bug light” works well for this purpose.

Scoop Coater: A metal trough used to dispense emulsion for the purpose of coating screens.

Screen: A wooden or metal frame with mesh tightly attached to it.

Solvent: A liquid that dissolves a solid.

Squeegee: Wooden or metal handled tool with a rubber blade used to drive ink through a stencil by pulling the squeegee across the screen.

Squeegee Side: The side of the screen the ink is applied to.

Spot Color:  Color reproduced by an opaque, premixed, standard ink chosen from a color system such as the Pantone Matching System

Stencil: The portion of an exposed screen containing the image to be printed.

Step Wedge Test – Exposure test to determine proper exposure time with a series of stepped exposures on one screen.

Substrate: Term for the item that is being printed.

Tension: The “tightness” of the screen mesh, measured in newtons.

Underlay: A thin coating of ink printed first and cured to act as a base for which all other colors are to be printed on. Underbasing is usually required when printing multi-color designs on colored shirts.

Underexposed: Insufficient screen exposure time, resulting in a soft stencil that can break down prematurely during the print run.

Vector Art- Images that use points, lines, curves and shapes based on mathematical expressions. These images are usually created in programs such as Illustrator, CorelDraw, or Photoshop to name a few. Vectorized files are often given in .ai, .psd, .eps., .pdf. These are the BEST possible files to give our art department.

Viscosity: Commonly perceived as the “thickness” or “thinness” of an ink.

Water Based Ink: Non plastisol inks that can be air dried.

Washout Booth :  Booth used for washing out stencils and reclaiming screens.

(For more definitions visit our sources used in the creation of this post: http://www.ryonetblog.com/screen-printer-terms/)

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