Terminology

Although not totally complete, the terms listed below will get you well on your way to understanding printer’s terminology.

Bleed - A bleed occurs when your color or image extends off of the printed piece, typically bleeds are created when the printed piece is trimmed.

CMYK - Cyan, Magenta, Yellow and Black are the colors used in 4 color process printing. On the printing press they are run in a specific order. Black, Cyan, Magenta and Yellow, the most transparent of the four and containing the most varnish in the formula is yellow and is laid down last. The most opaque color, black, is laid down first. Following this sequence allows for brighter imaging and better control of color.

Color Densitometer - A piece of equipment used by press personnel to determine the density of the ink color being laid down on the printed sheet. It has a numerical digital read out and the higher the readout on the densitometer, the greater the amount of ink that is being laid down on the sheet.

Color Density - The amount of ink printed on the sheet.

CTP - Computer to Plate. A process that bypasses the use of film when creating the image that is receptive to ink on the printing plate.

Emboss - Impressing an image by forming the paper using a die that is cast in the shape of the image you want to create. When pressure is applied, the paper takes the form of the die.

Film - A sheet of material that is processed with the image on it. This material will be placed over the printing plate and with the use of light, burning the image into the printing plate, determining the ink receptive areas of the plate.

Halftone - The screening of a continuous tone image, converting the image into different sized, yet, equally spaced dots.

Impression - Each time the sheet passes through the press and is printed, it is an impression. The terminology is useful in production scheduling and estimating because it determines the quantity of the run and the efficiency and speed of the press and the operator.

Large Format - A term that describes the printing of large sized substrates. Printed pieces would include large posters, POP (Point of Purchase) signage and banners. The equipment that is used to handle these items are typically inkjet printers.

Offset - The printing process that uses a blanket to receive the ink from the plate and then impresses it onto a sheet of paper as the paper passes between the blanket and a hard steel cylinder called an Impression Cylinder.

Perfect Bind - A type of binding that combines the cover and the inside pages on the spine with glue.

Registration - The alignment of dots in relation to each other. When the cyan, magenta, yellow and black plates are aligned and brought into focus, the printed piece is considered to be in register.

RIP - Raster Image Processing. A computer language that arranges the dots, solids, lines and type in a particular pattern concerning densities and angles. The function of the RIP is to send instructions to the film processor, telling the processor where to place each item and what angle each item is to be placed in relation to the other items on the film or combination of films used in creating the image.

Saddle Stitch - The binding of a book using wire staples on the binding edge to hold the book together.

Score - A crease that is impressed into the paper. Scoring will allow for exact folding on heavier stocks and helps to eliminate the cracking of some substrates.

Separations - In four color process printing you have a continuous tone image that is separated into four different colors, CMYK, enabling it to be printed. The process begins with scanning an image. The scanned image is then separated into the four process colors.

Sheet Fed Press - A printing press that prints individual sheets of paper as opposed to rolls.

Signature - A parent sheet that consists of 4, 8 or 16 pages depending on the size of the montage that is built for the press it is scheduled to run on. The signature is then folded, gathered with other signatures (depending on how many pages are needed to complete the project), glued or stitched and then trimmed.

Spot Color-PMS-Pantone - Colors that are mixed in batches and are identified by a number. The number can be followed by a C (Coated) or U (Uncoated). The formula is designed for the type of substrate it is to be printed on taking into consideration the porosity of the paper.

Trapping - The overlay or over printing of dots in relation to each other to compensate for miss-registration on the printing press creating an illusion of tight register.

Web Press - A printing press that prints from rolls of paper and is mostly used for longer runs.

Wiro Binding - A binding technique that winds a circular double-wire strip along the binding edge of the pages. Wiro bound books lie flat when open and are useful for manuals and calendars.