When studying screen printing, all the terminology you might hear is muddled.

Bitmap – An image created on a visual display unit where each pixel corresponds to one or more bits in memory, and the number of bits per pixel determines the number of colors available.Bitmap graphics are often referred to as raster graphics.

Haemorrhage – when the ink migrates out of the area it means that it occurs here this can be printed closely with 2 different colours as well as occurs.

Blend – Print two or more inks at the same time for a gradient effect.

Butt alignment – When the edges of two different print colors are side by side but do not overlap.

Burning screen – To harden the emulsion by exposing the prepared screen to very bright light.As soon as light hits the emulsion, the emulsion itself hardens.Wherever the film blocks the light, the emulsion stays soft and washes off the screen.All that’s left on the screen is the template.

Separations – When you send a panchromatic image to a screen printer, the separators figure out how to decompose the image for printing.This is done using bitmaps and halftones.

Coverage – The quality or quantity of ink deposited on a shirt when printed on a screen.Also known as opacity.

CMYK – Cyan, magenta, yellow and key or black.When you combine these four colors, you can make almost any color.This video discusses the differences between CMYK, RGB, and color matching used in screen printing:

DPI – stands for “points per inch”.This is a measure of print resolution that indicates how many single points the printer can produce in one inch of linear space

Dye migration – Occurs when printing on polyester shirts.On these shirts, the dye sits on top of the fiber in small droplets of steam.As you print, the ink passes through the dye, and as your shirt passes through the dryer, the vapor droplets change into gas and merge into the ink.This can change the ink color according to the color of the shirt printed on it.Example: White ink printed on a red shirt may have pink in it.

Flicker – The process of printing the same ink color twice on a garment.It is most often used when printing lighter inks on darker materials.

Floodlight – The act of spreading ink across a screen and then pushing the ink in.

Gap alignment – The alignment of an artwork in which there is a gap between one color and another.

Halftone – Halftone is the process of creating an image by using points of different size or spacing.The dots are so small that they merge together to create shades of various colors. 

Ink sink – The side on which the ink is placed on the screen.

Cull – The omission of artwork from the design to prevent other colours from being overprinted.See Mold.

LPI (lines per inch) – measures the print resolution.A line consists of halftones, which are created by physical ink dots during printing to produce different tones.LPI is a measure of the tightness of the lines in a halftone grid.

Screen – This is the material stretched over the screen frame itself.Different screens have different mesh number.The lower the number, the more ink is allowed.

Mesh number – this is the number of openings between the filaments in the mesh.Larger Numbers have smaller openings, and smaller Numbers have larger openings.Using a higher mesh number will have a softer feel.

Overprint – To print a color on another color.

PMS Color – PMS stands for Pantone Matching System.This is the way to consistently match the colors Pantone develops.The general standard in the screen printing industry is Solid Coated Book.

Registration – Alignment of one color of an artwork with another.Multicolor printing requires the different colors of the artwork to be aligned correctly.

Drain – A print that looks beyond the edge of a shirt or other printed garment.These prints work better on some garments than others (we recommend that your streamline design not cover any thick seams or pockets as this will break the continuous look of the print).

Spot color – Spot color is any color produced by a single print of ink.

Separations/Seps – After creating a work of art, each color must be printed on transparent film called separations.These will be used to burn images of each color to the screen.

Screen printing – The technical term for screen printing.

Trap – a three-color printing technique in which the base color “oozes” under the ink that will be printed on it.This limits the gap that can result from registration errors.

Vector graphics – In its simplest form, create vector graphics using lines and points rather than pixels.This means that it can be stretched or shrunk to almost any size without compromising the integrity of existing technology.

Under Background – When printing on darker clothing, a layer of white ink should be printed before any other color.This keeps the color realistic and keeps the opacity on the dark fabric.

Viscosity – often referred to as the “thickness” or “thinness” of an ink. 

equipment

These are the tools and equipment used in the screen printing process 

This is an automatic press that we operate in Cleveland, Ohio

Automatic printing machine – screen printing machine operated by electric motor and hydraulic system.Automatic screen printing machines are much more productive than manual printing machines and usually produce higher quality printing results.

Film/film positive – this is transparent “plastic” on which your work is printed in full black.

Printer/Paperpress reel – This is a square metal or wooden frame with a screen made of a mesh material and stretched tightly over it. 

Picture: The metal frame is a platen, and the inside screen is stretched and holds the artwork

Screen/mesh – Screen or artwork used to print a particular color.

Squeezer – This is a tool with a flat rubber blade on one side that is used to pull ink evenly across the screen.