A

Acetate: Clear plastic film, often used for registration, handmade transparencies, and wrapping mounted prints.

Acid Free Paper: Paper treated with a buffering agent to neutralize its natural acidity (occurring from the addition of wood pulp and/or sizing) in order to protect images from discoloration and deterioration. This is not the same as archival because the acidity will eventually come back, it may just take many years.  Beware of “acid-free” and choose archival when possible for truly long lasting.

Acrylic: A synthetic material made from polymers of acrylic acid or acrylates.

Archival Paper: An especially durable paper with long-standing qualities, acid free, lignin free, usually with good color retention. It is made from 100% cotton, rag, or other natural fibers and no fillers or neutralized acidic materials are used during its formation.

B

Bleeding: Occurs when an ink that is printed migrates outside of its printed area into surrounding areas.

Block Out: Substance that, when applied to the screen, will prevent ink from reaching the print.

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

C

Coating: The process of applying a liquid to a screen. Usually emulsion or screen filler.

D

Degrease: To remove grease, oil, or dirt from the screen by washing it with a chemical.

De-haze: To remove ghosted images or ink stains from a screen using a caustic cleaning agent.

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

Drawing Fluid: A water-soluble fluid applied to the screen to create a positive stencil. 

Durometer: The measure of the hardness or stiffness of a flexible rubber squeegee blade.

E

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).

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

Exposure Unit: A device that emits UV light used to expose an image onto the screen and make a photo stencil.

Extenders: Added to ink to increase its volume and transparency.

F

Face/Substrate-side: The side of a screen that touches the substrate.

Flooding: The first step when printing an image. With the screen slightly raised, ink is pulled across the image area, depositing ink into the image reservoir.  To print, full pressure is used to push the ink through the screen, to the substrate below.

Four Color Process: Color printing of an image using the specialty translucent colors cyan, magenta, yellow, and black (also known as CMYK).  It is the most common commercial printing process.

Frame: The rectangular wood or metal body used to hold the stretched mesh of the screen in a fixed position.

G

Ghost Image: A light, visible image in a screen caused by remaining ink from an earlier printing of the screen.  

H

Halo: A mark created during printing when the screen does not separate immediately from the substrate.

Haze removers: Chemicals used to remove ink stains or ghost images on mesh fabric.

Hot Pressed Paper: A paper surface that is smooth, produced by pressing a finished sheet through hot cylinders.

I

Impression: The resultant image when printing any matrix.

M

Matrix: From the Latin word mater, meaning mother, the matrix is a surface on which the image to be printed is prepared/created.

Mesh: The polyester material stretched over the frame through which the ink passes.

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.

Monoprint: Unique, non-repeatable print pulled from a matrix that already has an image on it, in contrast to a monotype, where the surface is bare and unworked.

Monotype: A form of printmaking in which the artist creates an image on some material, such as the mesh of the screen, glass or a plastic film, and then prints the image onto paper. The residual pigment can then be reworked or added to, but the subsequent print will not be an exact version of the previous print. Monotypes may be unique prints or variations on a theme.

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

MSDS: "Material Safety Data Sheets." A Government required safety document that outlines information and procedures for handling and working with all manner of chemicals.

Mylar: A plastic film, often frosted or semi-transparent.

N

Non-Toxic: Not containing or caused by a toxin or poison. Not capable of causing harm. 

O

Off-Contact: 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.

P

Pinhole: A small, unintended hole in the stencil where ink can cause a small dot to print on the substrate. Also called a “holiday”.

Planographic: The printmaking processes (generally screen print and lithography) used to print impressions from a smooth surface rather than creating incised or relief areas on the matrix.

Positive: Any media used to completely block out UV light in the image area during the exposure process.

Print: Technically, a print is any image that is transferred from a matrix onto a substrate.

Printable Area: The area of the screen where the image can be placed without distortion during exposure or printing. This will tend to be center balanced.

Proof: A sample print. Also known as a test print.

R

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

Reducer: Chemical used to lower the viscosity of inks.

Registration: The alignment of images as they are printed sequentially onto the same substrate. There are many types of registration depending on the level of precision required.

Residual ink Film: The ink remaining in the mesh of the screen after the image has been printed.

S

Scoop coater: A long trough-like device used to apply liquid to the screen mesh. Also referred to as a coating trough.

Screen: The complete printing unit made of tightened mesh attached to a stable frame (usually wood or metal).

Screen Filler: Material applied to the screen to “block-out” or prevent the non-images areas of the image from printing.

Screen printing: The act of printing with a screen, stencil, and squeegee onto a substrate. Also called serigraphy or silk screen, screen printing is a printing process based on the stencil principle. A fine woven fabric is tightly stretched and attached to a sturdy frame to form the printing screen. A stencil is created on the screen by applying a “blockout” (glue, paper, film, emulsion or screen filler) to all non-image areas. Ink is then applied to the entire screen using a squeegee which forces the ink to pass through the open area of the stencil onto an underlying substrate such as paper, wood, or fabric. 

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

Size/Sizing: Glutinous material made of flour, varnish, glue or resin that is used to fill the pores of paper and slow down its properties of absorption. Can be added during or after the forming of the sheet.

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

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

Spray Tack: Aerosol spray glue (most often non-permanent or repositionable) used to keep the paper in a fixed position while printing.  

Squeegee: The flexible rubber blade and accompanying handle that transfers ink through the mesh and stencil of the screen onto the substrate underneath.

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

Substrate: The surface or material to be printed onto (paper, wood, fabric, etc).

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

Stencil Remover: A substance that removes the stencil from the screen. Different chemicals are required for different types of stencils.

T

Transparent Base: A colorless substance used to extend ink, increase its translucency, and improve its consistency.

V

Vellum: was originally a translucent material made from animal skin. Today it is a translucent paper product sometimes used to make positive images.

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

W

Watermark: Slightly thicker part of the papermaker's mold, usually in the form of a design, which indicates the manufacturer of the paper. The watermark is thinner than the rest of the sheet and usually located in a corner or along the side. 

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

Washout Booth: The piece of equipment used to wash screens in. It will generally have a light in the back so you can see through the screen as you work. Several steps in screenprinting are actually done here.

Water-Based Ink: Inks that can be air dried and thinned with water.

Water Leaf: A paper with little or no sizing. Very absorbent.

Waterproof: Not able to be dissolved in water.

Water-soluble: Able to be dissolved in water.