Glossary of Print Terms

 

A lot of terminology gets thrown around when you are planning a print project. Hopefully this list, and our Blog posts, will help demystify some of the more common terms.  And of course, your Mercury Customer Service will be more than happy to explain any aspect of our process that you are unfamiliar with.

 

Accordion Fold

A fold with 4 panels or more, with folds alternating on each panel; an attractive design for some applications, but can spring open during the insertion process.

Author's Alterations (AA's)

During the proofing stage, these are corrections that are made by the printer at the request of client free; not caused by printer error.

Barrel Fold

Similar to a roll fold, a barrel fold has 3 panels or more with folds in the same direction, cause the end user to “un-roll” the fold to view in its entirety.

Basis Weight

the weight in lbs of 500 sheets of paper cut to a specific size of the corresponding grade of paper.

Bind-In-Card

A card, generally the size of a post card, that is bound into a signature. A good example is a magazine subscription card printed on 7 pt reply card.

Blanket

A printing blanket is a rubber-like material that receives ink from the printing plate and transfers it to the printing substrate.

Bleeds

A bleed is a printed image in which the ink extends to the edge of the sheet. Bleeds generally call for a small margin of overprint to ensure that the bleed truly extends all the way. 

Blow-In-Card

Bond Weight

Bond weight is a measurement, in lbs, of a ream of 500 sheets of paper measured 17” x 22”, generally uncoated, and is common in forms and envelope production. Common weights are 16 lb – 40 lb, and increase by 4 lb increments. 

Book Weight

Book weight is a measurement, in lbs, of a ream of 500 sheets of paper measured 25” x 38” which can be coated or uncoated. Some book weight grades contain ground wood. Book weight regularly referred to as “offset” and “text” weight.

 

Common book weights range from 30 lb – 100 lb, coated and uncoated, in 5-10 lb increments.

Booklet Fold

A booklet refers to a fold that includes a right angle, and is still connected as 1 sheet of paper without glue.

Brightness

Brightness is a value, from 0-100% that indicates impurity in paper. Standard 50 lb offset, for example, is 92 bright. Some premium grades are 98 bright, while newsprint grades that contain ground wood may be in the 60s.

Bristol

Bristol weight, commonly referred to as “vellum Bristol”, is the rougher printing substrate cousin to the uncoated cover grade. Bristol is measured as 22.5” x 28.5” and has common weights from 80-200 lb, in increments of 20 lb. 67 lb vellum Bristol is the exception, and is a common choice for yielding 9 point caliper.

Buck Slip

A buck slip is a direct mail component part, generally used in combination with a form or generic letter, indicating the special value of the offer in the letter with graphics and few words. It’s intended to hook the end user into reading the form.

Calender

Calender rollers are used in the paper making process at the very end of the machine. These calender “stacks” require the web to weave through the rollers with tremendous pressure, causing the paper to become smoother. A very smooth paper, like a smooth offset or a gloss stock, is considered very well calendered.

Caliper

Caliper, as it relates to paper, is the thickness of the sheet.

Chill Roller

Chill rollers are employed after the oven on a heatset press to cool down the sheet quickly. This allows the ink to set properly.

Clamp Truck

A clamp truck is a fork lift with a special clamp where forks would normally be. They use hydraulic pressure to lift and rotate rolls of paper that can weigh 2000 lb or more.

CMYK

Cyan, Magenta, Yellow, Black (or Key). These are the four process colors required for process color printing. See also 4CP.

Collate

Collation, as it refers to a direct mail piece, means that all sides have been trimmed and sheets are slit loose.

Color Bars

Color bars are a common application on sheeting presses. Each color that is laid down on the sheet also gets a narrow bar across the bottom of the sheet. This allows the operator to measure density across the web to ensure even color throughout the print run.

Colorant

A colorant is the pigment that gives ink it’s desired color.

Combination

A combination run, as it relates to printing, is a group of 2 or more images run on one set of printing plates and then separated in the finishing stages. Combinations offer an economical solution for jobs with multiple codes and like quantities.

Commercial Printing

Commercial printing, dominated by offset lithography, is one of the largest and most important segments of the graphic arts community.

Conditioning

Conditioning is the act of bringing paper into a temperate pressroom climate to mitigate curling and static electricity, among other potential issues.

Continuous Forms

Continuous forms are commonly purchased for use at lettershops. The forms, which can be fan folded or rewound on rolls, have a generic image and message that repeats throughout the run. The letter shop then runs these forms through lasers to “personalize” the letter with information like offer rates, dates, names, and more.

 

Continuous forms are a cost effective way to personalize direct mail packages.

Continuous Fold Feeder

Also called an over-under folder, these folders have a feed boards that are continually fed at a slight angle, ensuring the folder will never have to stop.

Cover Weight

Cover weight is a basis weight of 500 sheets of paper sized 20” x 26”, and is generally synonymous with high quality printing. With weights ranging from 50-170 lbs, in 5-10 lb increments, this paper can be coated or uncoated.

 

While 50-100 lb cover products can commonly be found as web, thicker cover stocks are usually only sold as sheets and are subsequently classified for sheet-fed presses.

CTP

Computer to Plate is a practice that allows plates to be electronically made in minutes instead of hours. All of Mercury's facilities have CTP machines for fast prepress turnaround.

Cure

Curing is the act of removing certain elements from the ink once applied to the paper to help it dry and set properly.

Cutoff

A cutoff on a printing press is the length of the circumference of a blanket cylinder on a web offset press.

Dampening System

A dampening system on a printing press applies a water based fountain solution to the plate to repel ink from non-image printing areas.

Densitometer

A densitometer is a tool employed at most presses; it ensures even ink film distribution throughout the press run. Densitometers are digitally calibrated at our facilities regularly.

Density

Density, as it relates to print, is the thickness of ink film that is laid down on each impression. Density is controlled by ink flow and is measured by densitometers to ensure high quality. Mercury employs the GRACOL standard for density range as a guide to achieve proper color.

Die-Cut

Die cutting is a finishing operation that uses a steel die to cut a predetermined pattern in the paper. Small die cutting jobs can be done inline on some presses, while more complicated die cutting jobs require dedicated die cutting machines.

Dot Area

A measurement of dots in a given area from 0-100%.

Dot Gain

Dot gain is the difference is size from the dot on the plate to the dot on the printing substrate. Low dot gain is inherent of sharp printing; larger dots tend to result in darker, less sharp images. Prepress generally has computer software to create curves to minimize or compensate for dot gain.

Double Hit

Occasionally, a print run will require an intense amount of one color that can’t be applied with only one printing unit. If the press has enough available units, the image can be split up into two plates in order to create the image properly. This also occurs if the image is designed in a way that could cause ghosting. 

Drop-Shipping

Dull

Dull paper contains little to no gloss; very similar to a silk coated which is a sheen but not a shine. 

Duotone

A duotone is a grey scale or monotone image, that adds a second color to accent it. Tritones and quadtones use the same effect with 3 and 4 colors.

Emulsion

An emulsion is the green part on a printing plate that looks like the image. The emulsion attracts the ink where the rest of the plate attracts water (fountain solution).

Fan Folded Forms

Fan folded forms, a type of continuous form, is a never ending accordion fold stretch of forms, folded on a perforation at each repeat. They are generally packed in cartons.

Felt Side of Paper

While less noticeable on newer paper machines, paper has 2 sides – a smooth side and a felt side (the side that faces down on the wire screen during the papermaking process). The felt side can be slightly rough and in some cases prints differently than the smooth side.

Flat Size

The flat size of a piece refers to the full size it should be before it is folded or finished otherwise.

Flexographic Ink

“Flexo” is a water based ink type used primarily in envelope and carton production.

Fluorescent Ink

The true revealing characteristic of fluorescent ink is it’s ability to glow under ultraviolet light. This ink is generally very shiny and attention-grabbing without UV light.

Folded Size

A folded size is the final dimensions of a piece after it has been trimmed and folded.

Folding Sample

A folding sample is used in the folding department of pressrooms to ensure the fold is constructed properly.

Generally, meeting edges will have like letters or numbers indicating that the operator should meet the two edges (A to A, B to B).

Forms Ink

Forms ink, also known as “no heat” ink, is an ink that dries over a longer period of time because there is no curing process. Common in line copy, this ink does not perform well when there is a lot of ink coverage involved.

Four Color Process

4CP, also known as CMYK, is the process of laying Black, Cyan, Magenta, and Yellow in the proper order to create a full color image. 4 color process requires 4 print units for each side of the paper, and is very common in the print industry.

French Fold

A French fold is an uncommon but useful fold, folding a lip one way and then folding the opposite way to conceal it. This keeps the piece full size, superficially, and allows it to fit into common envelope sizes.

Fold

A commonly used fold for greeting cards, 6x9 envelopes, and more.

Forest Stewardship Council (FSC)

FSC is an independent, non-governmental, not-for-profit organization established to promote the responsible management of the world’s forests.

Free Standing Insert (FSI)

an advertisement, intended to be loosely inserted or to stand alone.

Fugitive Glue

Fugitive glue is a non-abrasive adhesive used to bind two substrates together, without causing damage when pulled apart. Also referred to as “booger glue”.

Ganging

Synonymous with a combination run, as it relates to printing, is a group of 2 or more images “ganged” one set of printing plates and then separated in the finishing stages. Combinations offer an economical solution for jobs with multiple codes and like quantities.

Ghosting

Ghosting is an artwork induced print production issue caused by inconsistent lateral coverage across the web, resulting in some parts being lighter and other parts being darker.

Gloss

A gloss coated stock is indicative of a shiny printing surface. Gloss stocks are smooth and highly “calendered”.

GRACOL

General Requirements and Applications for Commercial Offset Lithography, an independent task force formed to create general standards for commercial offset printers.

Grain Direction

the grain direction is the alignment and structure of paper fibers in a paper stock; grain short refers to the length of the fiber running perpendicular, grain long the fibers run parallel.

Grayscale

A monotone image with multiple shades of black.

Gripper Edge

In sheet fed printing or envelope folding, the lead edge of the sheet that is fed into the machine Half 

Halftone

an image made up of various sizes of dots and density to simulate gradient realistic images with one color.

Heatset Ink

petroleum-based ink that is cured with heat in an oven; heatset ink is most common in the publication printing industry, where ink coverage can be heavy. Heatset ink is a low cost solution to lay down heavy ink coverage.

Heatset Oven

a heatset oven is a tunnel for paper to pass through at a specific temperature to dry the ink quickly without damaging the web. 

Hickey

An undesirable small spec of dust or debris distributed through the roller train and caught on the printing blanket, cause it to repeat until it is noticed and knocked off.

Hone Off

The process of removing an emulsion on a printing plate using a special tool to reduce the number of plates needed.

Hue

Color apparent to the eye – red, blue, yellow IFU – instructions for use printing Image – One replication of the original artwork on a press sheet.

Imposition Software

Print production software that separates color into CYMK and allows images to be arranged properly on a printing plate for print production.

Impression

An impression is one full rotation Indicia – an indication of postage payment printed directly on self-mailers.

Indicia

An indication of postage payment printed directly onto self-mailers, and either the bottom left of the Front cover or the top right of the Back cover of a magazine. Alternately, it can be printed onto a Chesire Label.

Ink Fountain

One per printing unit, ink fountains allow the flow of ink throughout the roller train. Ink fountains can have keys that can be adjusted to control the flow of ink in certain spots across the web.

Ink Keys

Ink keys, controlled manually or remotely, allow a printing press operator to control ink flow across the web by moving them inward or outward via a screw – this is referred to as “setting color” or “setting ink”

Inkjet

An output device that forms a printed image by expelling tiny drops of ink arranged in pattern to create an image.

Jogging

In post-press production, this involves aligning printed sheets to facilitate further manufacturing processes like cutting, die cutting and folding.

JPEG

A common extension (.jpg or .jpeg) for files containing images.  It is an acronym for the Joint Photographic Experts Group, who standardized the term.  This is not the file type preferred for print, as the compression used can cause images to blur. 

 

Knockout Text

Knockout text occurs when a full color image has text “knocked out” of it; in other words, white text in the middle of an image.

Lab

A method of color measurement, using a 3D axis to create an infinite color pallet and measure color quantitatively.

Laser Cut Sheets

Designed for use with a sheet-fed laser printer, this type of printing uses laser-guaranteed paper and inks and requires flat delivery for perfect laser application.

Line Copy

Line copy is a way to refer to a document’s general makeup – line copy, as opposed to process color, is mostly comprised of text.

Lithography

The scientific name for web offset printing and sheet fed offset printing, in which an image on a printing plate is inked and transferred to a blanket, and then a printing substrate.

Lock-up

A lock-up is a term used to describe where the two ends of a printing plate meet; since no ink is transferred in a lockup, sometimes the lockup is moved to another area of the printed image so that the piece can bleed.

Matte

This is a type of paper coated that is calendared very little, and has a very dull rough feeling for a coated paper. It offers the least shiny coating surface, but benefits from being glare-free.

Metallic Inks

Ink made with metal flake offers reflective and attractive qualities; often comes at a price of 5x or more of standard PMS colors.

Misting

A print production problem when ink and water are not appropriately balanced, and ink spits onto the blanket bypassing the plate cylinder; this causes repeating small dots on a press sheet. 

Mottle

A print production defect when ink does not distribute properly, causing an uneven or speckled look.

Opacity

A measurement of the ability to block the passage of light through a printing substrate; measured on a scale of 1-100.

Packing

A special type of paper manufactured to exact caliper specifications, used to increase the pressure from plate to blanket in the printing process.

Pagination

The numbering sequence of pages in a document.

Parallel Fold

A parallel fold, also known as folding in half and half again, is a common way to get a 14” long form to fit in a # 10 envelope. This creates a 4 panel brochure. 

PDF

Portable Document Format. The preferred method of delivery for printable files.

Perfect-Binding

Add Description here

Perfecting

Perfecting is the ability to print on both sides in one pass; presses that do this are also called “blanket to blanket” presses.

Perforation

An operation which creates a series of small holes in a pattern so that a portion of the printed material can be detached easily.

PI

Short for “Product Insert”, this type of printing is found in many retail packages and is used to promote further the products for the manufacturer.

Picking

Picking occurs when paper fibers release too easily from the printing substrate or when ink is excessively tacky. These paper fibers can run through the roller train, eventually settling on a blanket causing a hickey.

Pile

A stack of printed paper that is jogged neatly waiting post print production operations.

Pile Feed Folder

Type of buckle plate folder that uses a pile to feed into the parallel section; efficient for high-speed one-man operation.

Pinholes

Tiny holes punched out on the sides of continuous forms so they can be fed through laser printers at letter shops.

Plate

A one-use metal sheet that contains an emulsion of the area to be printed, which is wrapped around a plate cylinder on a printing press.

Plate Change

Required to change copy on a job with similar images.

PMS Color

Pantone Matching System, a numbered color system that has a specific formula based on Pantone Mixing Bases or even process colors.

Pre-Flight

One of the main responsibilities of the Prepress department. The Prepress Operator checks incoming files for their suitability for printing. If there are aspects of the file that cannot be adjusted by the Prepress Department, the file may be returned to the customer for compliance adjustment.

Prepress

A term used to describe all of the processes that come before the print phase of production.  Includes preflighting, proofing, imposition, and platemaking.

Press Check

a pre-arranged client site visit to ensure that the color and quality of the product they are paying for meets their exact specifications. The customer will approve a press proof before the final product is run off of press.

Print Unit

A section of a printing press that can lay down one color on one or both sides of the printing substrate. It generally contains and ink fountain with ink keys, a roller train, a plate cylinder and blanket cylinder, and a water dampening system.

Proof

A representation of what an image will look like when printed. A proof will typically also contain markings to indicate final trim size, as well as to show whether enough bleed has been provided.

Pyrometer

A tool used to measure heat; in web offset printing, it’s often used to measure the heat of rollers and chill stack on the fly to ensure that all components run at the proper temperature.

Register

 the operation of lining up multiple colors in correct orientation with each other; product is said to be “in register” or “out of register”.

Registration marks

Targets printed in non-critical areas of the print intended to synchronize all printing units together. Typically in the shape of dots, crosses, or bars.

Reply Card

A special paper, often referred to as “hi-bulk”, made not only to caliper to minimum postal standards, but to be a very cost effective method for return mail.  Commonly used on Business Reply Cards.

Resolution

Measured in many different ways, like DPI or PPI, resolution refers to the measurement of clarity of a reproduction of an image.  

 

You will commonly hear this referred to when an image file is either high or low resolution.  Low resolution for a print image is 72 DPI, whereas high resolution is anything 300 DPI and above.  

 

We prefer 300 DPI for all images used to print, and try not to accept any image below 150 DPI.

RGB

RGB is the acronym for "Red Green Blue", which are the primary colors of visible light.  

 

RGB also commonly refers to the image color format that most cameras use to save files.

 

RGB image files need to be converted to CMYK format before printing, which can change the image slightly.

Right Angle Fold

A type of fold that folds in one direction, and then folds in a perpendicular direction to the original fold.

Roll Fold

A multiple panel fold with all folds in the same direction.

Roller Train

 a series of rollers with the job of smoothing out ink to be laid on the printing plate – measured by linear ink storage.

Saddle Stitching

Affixing multiple pages together, generally with the binding material shown on the outside and center of the finished product.

 

In magazine production, this is done using staples, and is the common method of binding publications with less than 50 pages.

Samples

Representations of the print and fold quality during the print run; also used to create sample packages. 

 

Samples are always sent to both Mercury and the customer to verify quality.

Satin

a coating finish characterized by sheen; not as shiny as a gloss finish, but shinier than a dull or matte finish.

Score

An indentation on a printing substrate to allow the piece to fold easily without the paper or coating cracking.

Screen

A dotted half tone of measured in strength by percentage, used to maintain ink film density on press while making a color appear lighter.

Scumming

A greasy film of ink that can be caused by too little water. This is an undesirable print production issue, and one that is avoided whenever possible.

SFI

Sustainable Forestry Initiative; a certification audited by an independent 3rd party to ensure that the end user receives pulp and wood products from a responsible source.

 

All of Mercury's print facilities are SFI certified.

Sheet-Fed

Offset presses designed to print on single sheets at a time.

Signature

Printed sheets that are generally folded to size in 4, 8, 16, 32 or 64 page increments.

 

Mercury can print signatures up to 32 pages per signature.  The larger the signature the more efficient and less costly your publication will be. 

Slit and Nest

A type of fold, 6 pages or more, in which the outside cover is connected but the inside pages are loose.