Glossary

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Adhesives
Three unique adhesive formulations for seam gumming,window patching and flap sealing are used in envelope construction. Seam gum is sometimes called “back” gum.
A-Style
Announcement style envelopes are used for social correspondence. Open side, side seam with a square flap. A-styles come in six standard sizes. A-styles are not machine insertable.
Automatic Die-Cutter
A programmable machine that automatically cuts multiple envelope blanks out of a larger sheet. Programs in the machine’s memory can be recalled to repeat common standard sizes or custom jobs.
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Back
Part of an envelope which the seal flap affixes to when sealed. A specific part of an envelope blank extending from the bottom fold forming the throat of an envelope.
Back Gum
Seams that form an envelope are on the back. The gums used to fasten these seams are sometimes called “back-gums” Also, see adhesives, Seam gum
Baronial
Envelope style used for social stationery and greeting cards. Open side, diagonal seam with a pointed flap. Baronial style envelopes come in five standard sizes. Baronial style envelopes are not machine insertable.
Basis Weight
Term used to describe the weight of 500 sheets, one ream, of a standard sized sheet of paper.
Blank
Individual die-cut shaped flat sheets of paper that are folded to make an envelope.
Bleed
An extra amount of printed image that extends beyond the trim edge, fold or off the edge of a sheet or envelope blank.
Booklet
Open side, side seam envelopes available in many sizes. Booklet envelopes that exceed 6" x 9" are called “flats” and require additional postage to mail.
Bottom Flap
Part of an envelope blank that folds up from the bottom score to create the back of the envelope.
Bang Tail
A booklet style envelope with an extended back flap or “tail”. The tail is often perforated at the throat and printed as an order form.
Business Reply
A printed envelope included in a direct mail package provided by the sender to facilitate return of the customers' remittance postage paid.
Business Return
A printed envelope included in a direct mail package by the sender to facilitate return of the customer’s remittance at customer’s expense.
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Catalog Envelope
Open end, center seam. Catalog envelopes come in many sizes. Catalog envelopes exceeding 6" x 9" mail as “flats” and require additional postage. Catalog envelopes are not machine insertable.
Center Seam
A seam found in the middle of the back of catalog and coin envelopes.
Clasp Envelope
A reusable closure where a bendable metal tab is riveted to the back of the envelope. Clasps are most commonly used on catalog envelopes.
Close Registration
Refers to the position or alignment of copy relative to some fixed point of reference or when printing two or more colors that are printed side by side in extremely tight proximity. See Traps.
Coated Paper
Papers that have a gloss or matte surface. Coated papers are made with coating on one side, (C1S) or on both sides, (C2S). Coated papers provide a superior base for inks that results in clearer more dramatic color and image.
Corner Card
The return address in the form of type and/or logo in the left hand upper corner of an envelope.
Coatings
Water based clear sealant over-print applied on press to create special visual effects, protect against scuffing or encapsulate slower drying pigmented inks so that sheets can be die-cut and folded quickly. See Coatings and Varnishes white paper.
Color Management
The science of accurate and consistent color reproduction across multiple printing processes and presses. Color management uses special software, calibration tools, materials and operating procedures to achieve precise color matching and minimize color variation.
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Die Cutting
Process of cutting paper into envelope blanks using a steel die.
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Embossing
A process of stamping a decorative pattern into paper using pressure and an engraved roller or raised die to achieve a raised or depressed surface.
Envelope Blank
A shaped flat piece of paper that is scored and folded into an envelope. Blanks vary based on the size, style, flap and throat specifications of the envelope. Envelope folders that process blanks are called “blank-fed” folders.
Envelope Folder
Machines used to fold envelope blanks or narrow web rolls into finished envelopes. Folders can be product and size specific. Of modular construction, a folder may have sections to perform special operations such as panel cutting and patching, application of various types of closures as well as in-line printing flexographic printing presses.
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Face
The front side of an envelope. The side the seal-flap extends from. It is opposite the side the seal-gum sticks to.
Flap
There are three types of flaps on an envelope - Side, Bottom and Seal. The Side flaps are the tabs that are folded and gummed to form the envelope pocket. The Bottom flap is the protion of the envelope that folds up and is sealed along the sides edges to the side flaps to form the pocket. The Seal flap is the flap that is folded down and sealed after inserting contents. Seal flaps may have remoistenable, latex or peel and stick adhesive closures. Seal flaps may be square, pointed or tapered. Standard flap styles such as Commercial, Square, Pointed and Wallet are specified depending on the envelope's intended use. Commercial flaps are designed to be compatible with automatic inserting and sealing machines. Square and Pointed flaps are used in social correspondence, invitations and greeting card envelopes. Wallet flaps' extended length and over-sized gum pattern are used to seal securely and enclose thick multi-page contents.
Flexographic Printing
“Flexo” as it is called, is a print process using water based inks transferred by special rollers onto a raised type printing plate that applies the image directly to uncoated paper. Flexo print units mounted within the envelope folder allow for economical print and fold in a single operation. Time consuming make-ready means flexo is best suited for runs over 200M. Flexo image quality is good for type and line copy. Flexo is not a substitute for offset if precise color match, process build color or coated papers are required.
Full Gum
A continuous remoistenable gum line applied to the seal-flap.
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Halftones
Images that are converted into a pattern of precisely sized and positioned dots. The number of dots per inch determines clarity of image - more dots per inch produces a sharper image.
Heavy Coverage
A graphic design featuring a heavy concentration of color or images.
Heidelberg Press
A state of the art flat sheet offset printing press for sheets up to 28” X40”. Finest print quality available. The number of color or coating units varies by press. Minimum 4 color units required to print photographic quality process color. Typical presses have 4-8 color units plus additional units to apply coatings and varnishes. “Perfecting” presses can print both sides of the sheet in one pass.
Height
With the flap/opening at top, pointing to 12 o’clock, height is the vertical dimension of the envelope (or window on the envelope).
High Definition Envelope
A full color printed envelope featuring brilliant colors and evocative images. HD Envelopes are designed to stand-out in the mailbox, pique interest and get opened. Used by direct mailers, HD Envelopes are proven to lift response rates and improve ROI.
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Inside
The side of the envelope that will be inside the envelope after folding.
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JET Printing
An offset printing process that imprints folded envelopes on a small 2-5 color printing machine. JET delivers offset quality with some limitations on copy position, resolution and registration.
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Line Copy
Copy suitable for reproduction without using half-tone screens.
Logo Color
A proprietary color formulation associated with a trademark protected logo, i.e. Coca-Cola red, Kodak yellow, UPS brown.
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Makeready
The work done to setup a folder or press to run a job.
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Offset Lithography
The process of using an intermediate blanket cylinder to transfer an image from the plate to the paper. Offset provides superior image quality compared to other printing processes.
Outside
The side of the envelope that will be outside of the envelope after folding.
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Pantone Matching System (PMS)
Pantone Matching System: Frequently abbreviated to PMS, the Pantone Matching System is a book of standard printing industry ink colors with various shades of each color. These colors are used to identify the colors used for printing as well as for matching.
Poly
A clear, translucent and recyclable material that is used to cover a window in an envelope.
Process color
Printing from a series of two or more half-tone plates to produce intermediate colors and shades, i.e. four color process (4CP) uses four half-tone plates, one each for yellow, magenta, cyan and black to create realistic photographic quality images.
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Score
To impress or indent a mark or rule in the paper to make folding easier.
Score line:
A crease embossed into the paper to facilitate folding.
Seal Gum
The adhesive that affixes the flap to the back of the envelope to close it. Typically remoistenable or latex.
Seam
The area that is glued to form the envelope – depending on construction seams can be side, diagonal or center seams.
Seam Gum
Seam gum is also called Back Gum. This is an adhesive that cannot be remoistened. It is a sealant used to adhere the seams of the envelope that form the envelope pocket.
Security Tint
A pattern printed on the inside of the envelope to make the envelope more opaque so that contents cannot be read through the paper. Security tints are usually printed using flexo in-line as the envelope is being folded.
Set-off
When the ink from one sheet rubs off or smears onto the next sheet or envelope as it is being processed.
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Throat
The opening at the top of the envelope. To calculate your throat, measure from the top edge of the bottom flap to the fold line of the seal flap.
Tight Registration
Sometimes called hairline registration, tight registration refers to designs which feature two or more colors touching each other, or colors that are less than 1/16" from each other.
Top flap
The flap at the top of an envelope that has an adhesive to close the envelope.
Trap or Trapping
Trapping is a prepress technique, also known as spreading and choking. It consists of creating small overlaps between abutting colors in order to mask registration problems on the printing press later on in the graphical production.
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Uncoated Papers
Paper which does not have a coated surface, i.e. wove, vellum, smooth finish paper.
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Varnish
Varnish is essentially ink without pigment. It requires its own printing unit on a printing press. It can be wet-trapped (printed in-line at the same time other inks are laid down), or dry-trapped (run as an additional pass through the press after the initial ink coating has dried). The latter often provides a glossier finish. Varnish comes in gloss, dull, and satin (in-between dull and gloss), and can be tinted by adding pigment to the varnish.
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Wallet Flap
A rectangular square seal-flap designed to assure secure closure when there are multiple inserts in the envelope. Wallet flap style envelopes are not machine insertable.
Window
An opening cut out of the face or back of the envelope which allows the addressed insert to show through. Windows can be patched with plastic, cellophane or glassine patch material or left open with no patch.
Window Gum
A type of adhesive that is used to secure patch material to the envelope blank.
Window patch
A plastic, glassine or acetate material glued over the window opening.