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Acidity – refers to the PH (the acidity or alkalinity) of the paper. All of our paper is acid free. This does not make it truly archival, but it is definitely anti-tarnish and anti-yellowing.

Archival paper- neutral PH paper created especially for longterm, indefinite, storage (hundreds of years).

Adjustable Cutting Blades – blades which can be varied in size to produce envelopes of different sizes, including seal flaps of different lengths and shapes. Used when we do not have the correct size high die, or when the use of “blades” can increase the number of envelope blanks that can be cut from a given size sheet of paper, or when the quantity is too small to justify the expense of an $1100 or higher, high die.

"A" Size
– Announcement size. A rectangular envelope whose square seal flap stops at the midpoint of the backside of the envelope. Common sizes:
A-2 (4-3/8 x 5-3/4), A-6 (4-3/4 x 6-1/2), A-7 (5-1/4 x 7-1/4), A-8 (5-1/2 x 8-1/8)
A-9 (5-3/4 x 8-3/4), A-10 (6 x 9-1/2).
All of these sizes meet the USPS aspect ratio requirement for mailing at first class letter mail rates.

– historically a clean sharp paper-based physical image (picture) of what is to be reproduced. Now nearly obsolete in favor of electronic art.

Aspect Ratio- A USPS term referring to the relationship of the width (length) of an envelope divided by its height. For further specifications please see Letter-Size mail.

Avpexine – the most commonly used film for providing the patch, or window covering material. Commonly called “Poly”, it is not biodegradable. Other films include Tricyte (clear and also not biodegradable) and glassine which is somewhat cloudy but is biodegradable as it is made from wood.

Banding- a relatively inexpensive way to separate envelopes into small bunches of as few as 8 to a maximum of 50 envelopes. Automatic banding is done with paper bands, manual banding with rubber bands.

Bangtails- A one-way response/remittance envelope that has a tearoff coupon for returning information of all kinds (addresses, orders, etc.). Commonly mailed to the recipient in a #10, or included as a stuffer in a catalog. Alternatives include Kost Kuts and Hitchikers. We inventory #9 size (3-7/8 x 8-7/8) in 3 configurations: plain, with an easy opening backside for ATM use, and imprinted with Bank-by-Mail copy.

Bar Code – a series of long and short (about ¼” and 1/8”) vertical bars that represent the ZIP code of the addressee. Obtained from the Post Office, or included with bar code software.

- A squarish envelope made with diagonal seams and a longish pointed flap that ends below the mid-point of the back of the envelope.
Common Sizes: 4 Bar (3-5/8 x 5-1/8), 5 Bar (4-1/8 x 5-1/2), Astor (3-5/8 x 5-5/8)
5-1/2 Bar (4-3/8 x 5-3/4), Belmont (4-1/4 x 6-1/4), 6 Bar (4-3/4 x 6-1/2), Jay (5-1/8 x 6-7/8), Lee (5-1/4 x 7-1/4).
All of these sizes fall within the USPS aspect ratio standards for mailing at 1st class letter mail rates.

- an envelope that has been cut into the shape of an envelope, but not yet folded.

Bleed- a printing term that means the ink runs off the edge of the sheet, or folds over to the other side of the envelope. Envelopes with bleed copy generally must be printed in a flat sheet before the blanks are cut. To achieve a bleed effect at a score line (for example at the seal flap fold) the copy should wrap 5/32” to the other side of the envelope to avoid white showing where it is not wanted.

– A writing grade of paper measured on a 17 x 22” basis. Common weights are 20 lb. ( per 500 sheets), 24 lb. and 32 lb. Unlimited selection of grade, sheet sizes, colors, finish, etc. from your local paper merchant. 24# is usually ideal for converting into envelopes.

Booklet- any open side (opens on the long dimension) envelope constructed with 2 side seams and a square seal flap (usually 2” on envelopes 6 x 9” or larger, and proportionately smaller on envelopes less than 6” in height). The advantage of booklets is that they can be automatically inserted (unlike an open end such as a 9 x 12 catalog).

- the capacity of paper to reflect light. The higher the # the brighter, but not necessarily better as strength and opacity are compromised to obtain the brightness. Most 24# white wove envelope paper has a brightness of between 84 and 89.

BRE – Business Reply envelope. Specifically refers to a USPS approved format that allows a mailer to receive First-Class Mail back from customers without the customer having to pay postage. The mailer pays the postage and fees upon the return of the envelopes to the Post Office.

Bulk Pack
- the practice of putting envelopes directly into a carton without first being put into an inside box (usually of 500). Saves raw materials and the filling of land fills, but can be detrimental to long term storage of envelopes unless the fit is perfect.

Button and String- a method of holding seal flaps down. Uses include interdepartmental mail. Supplanted by Peerless Tac, and in some cases Velcro.

- a master container usually made of brown (unbleached) fluted corrugated stock.

Center Seam
- refers to the construction (click here to visit How to Build an Envelope) of an envelope that has a seam down the middle of its back, and across the bottom. This construction is preferred for making envelopes that open on the narrow (short) dimension, called open end envelopes, but can also be used for envelopes opening on the long dimension (open sides).

– refers to cardboard type material used for making folding boxes. These boxes have little structural integrity unless they are filled with the correct size envelope, in which case they become stiff as bricks.

Clasp- a metal seal flap closing device meant for repeated opening and closing. Somewhat replaced by reusable Latex seal &/or Peerless Tac.

Coated Paper
–paper that is made with a clay coated surface on one side (C1S), or both sides (C2S) of the sheet to enhance its appearance and printing qualities. Finish can range from dull (or matt) to a high gloss. For good folding characteristics the caliper must be a minimum of .004” for C1S, and 0045” for C2S.

Coins – small open end envelopes, usually made with center and bottom seams.

Commercial- the most common style of envelope used in the USA. Open side (opens on the long dimension) and made with diagonal seams.

– refers to the practice of making envelopes from sheets of paper supplied by a printer, paper merchant, or end user.

Corner Card – the return address (logo, typeset, or both) of the sender which is located in the upper left corner of the envelope. Usually 3/8” from the left, and 3/8” from the top (of a #10).

Courtesy Reply
– unlike a BRE, the customer pays the reply postage by following instructions such as Place Stamp Here.

Cross Grain
– grain going 90 degrees to the direction it should for making or folding envelopes. When paper is made it is formed with its grain (the orientation of the cellulose fibers that give paper its strength) all going in the same direction. When envelopes are die cut out of the sheet into blanks, it is critical that the grain go in the correct direction. Cross grain envelopes have the grain going perpendicularly to the correct direction, which can create excessive seal flap curl, puckering of the glued seams, and rollouts on the side scores.

Cylinder Die Cutting – refers to using a beefy horizontal printing press with a steel rule die mounted thereon for cutting out envelope shapes one sheet at a time. Time consuming, but for intricate shapes and small quantities it can be the most cost effective solution.

Deckle Edge – refers to an envelope made from paper which was formed with deckle, or serrated, edge. The envelope die is overhung off the sheet as the blanks are cut in order to preserve the deckle.

Diagonal Seam
- the most common form of envelope construction.

Die – a precision made cutting tool, forged into the desired shape for cutting envelopes. Commonly 4” high and ½” thick at the top. Costs about $1100.

Die Cutting- the process of manually cutting a lift of paper (usually 200-300 sheets) into envelope blanks with a minimum of spoilage. Other cutting methods include automated programmed cutting, adjustable blades, cylinder die cutting, or, for runs in the millions of envelopes in-line cutting or off-line AMC high speed die cutting.

Doorknob hang-up envelopes – envelopes made expressly to be hung up on a door knob for a variety of reasons: bill payment, fundraising, delivery info, etc. We manufacture and inventory these in white and colors, in addition to weather proof paper for leaving them hanging outside.

– a printing technique for obtaining enhanced results by holding the halftone dots in very close register.

Ears – malformation of one or more corners of an envelope caused by the top score or side score being out of position.

Electronic art- paperless art used for graphic arts reproduction.

Embossing – a process for raising paper to form a pattern, usually done with pressure and heat at slow revolutions per minute. However, simple patterns can be embossed at high speeds on some folding machines as the envelope is being formed.

Expansion envelope – envelopes made with a gusset on all 4 sides to accomodate thickness. The degree of expansion can range from ½” to 3”.
Note: when an envelope’s contents are thicker than ¼” and you wish to avoid paying for an expansion envelope, use a flat mailer such as a 9 x 12 or 10 x 13 but be sure allow an extra inch or more around the edges of the insert.

– the front of the envelope, as contrasted to the back.

– facing identification marks. A pattern of vertical bars printed in the upper right portion of the envelope just to the left of the indicia, used by the USPS to identify the envelope’s orientation.

- surface properties of paper. They include smoothness, gloss, absorption, texture, hold-out. Common finishes include wove (#1 for envelopes), laid, linen, vellum.

Flexography -letterpress printing (the actual plate that does the printing comes in contact with the paper being printed). The inks can be either water or alcohol based. For environmental reason we use water based inks. Screens should be no more 85 line, vs. 110-130 for offset.

Glassine- older style window film that is 100% green. Biodegrades quickly, but also is hydroscopic and takes on moisture if stored in a humid area. Poor readability at the USPS due to a usually cloudy appearance. Relatively short shelf life, which high relative humidity can make even shorter (a few months).

Grain – orientation of the fibers in the sheet of paper being cut into envelopes. In booklet and center and bottom seam style envelopes it is critical that the grain go straight from the top to the bottom of the envelope. Interestingly, grain direction is not important with diagonal seam envelopes.

Gripper– the leading edge, or gripped edge, of paper as it is pulled through the cylinders of a printing press. In general sheet fed offset presses use mechanical grippers to advance paper through the machine. Envelope machines use a combination of pusher pins and vacuum cylinders to move an envelope blank.

Guide edge
– the edge of the sheet that rubs against the side of the press to get its left/right positioning.

Gum- another name for the adhesive used for seal flaps and seams. Years ago this was animal (horse) derived, but now is starch or resin based.

Grade- refers to the kind of paper vs. substance weight.

Hitchhiker – a 2-way envelope for imprinting on small presses.
Size: 10” x 9-1/8”flat; 4-1/2 x 9-1/8” in the mail; 3-3/4 x 9-1/8” return envelope.
4-1/2’ x 9-1/8” order form and 1-1/8” x 9-1/8” customer receipt.
Inventoried in white, yellow and pink.

Holes- opposite problem from ears, but also created by the top and bottom scores or side seam scores being misadjusted.

Indicia – postage permit printed in the upper right of an envelope, and negates having to apply postage separately.

Inside side seams
- seam construction of an open side envelope where the back panel folds on top of the small 1” (usually) side seams that form the envelope.

Inside tint – the printing of an opaque design on the inside of an envelope to increase its opacity, and stop peeping eyes from reading what’s inside the envelope. By step-and-repeating a logo as the design, the security tint can also become an attractive addition to a company’s print media.

Kost Kut – another name for a remittance envelope whose seal flap is nearly as long as the height of the envelope. We inventory size 6-3/4 and #9.

– grade of paper that is stronger than wove, generally at commodity pricing levels. Available in white and brown.

Latex- adhesive used to stick seal flaps down by pressing the latexed seal flap against the latex on the body of the envelope. Latex sticks to latex, but nothing else. Shelf life is not more than year. Adhesion is quickly and adversely affected by dust.

Letter-Size Mail
– Mail that qualifies to be mailed at one ounce first class postage rates. The aspect ratio (the ratio of the envelope width to the height) must be between 1.3 and 2.5, and the thickness not more than ¼”, nor less than .007”. For example, an envelope with the height of an A7 (5-1/4”) when multiplied by 1.3 (the minimum width multiplier) could be as short as 6-7/8”, or, when multiplied by 2.5 be as wide (long)as 10-1/2”. If outside these dimensions, 2 ounces of postage is required even though the envelope and its contents weigh less than an ounce.
The minimum mailable size is 3-1/2” x 5” (regardless of postage), and the maximum size that can be mailed at the one ounce rate is 6-1/8 x 11-1/2. Note that at this large size the envelope plus as few as (3 or 4) 8-1/2 x 11 letterhead size sheets will probably weigh more than an ounce.

Litho – another term for offset printing. The plate with the image comes in contact with a blanket (originally a flat stone) which then contacts the paper.

Litho converting - refers to the making of envelopes from printed sheets previously imprinted with the images of anywhere from 1 to 50 envelopes which are then die cut and folded into envelopes. Large solid areas of ink may require extra drying time to avoid smudging.

– Roman letter for 1,000, which is the common quantity and pricing count for envelopes. i.e. price per 1,000 envs.

Opacity- property of paper that governs the degree to which light can pass through . The more opaque, the more difficult it is to see what is inside the envelope. The printing of an inside tint can increase opacity.

Open End- an envelope that opens on the short dimension. Construction can be center and bottom seam, single side seam, or even 2 side seams.

Open Side
– an envelope that opens on the long dimension. Usually diagonal seam or 2 side seam construction (with 1” side seams), but can also be made with center and bottom seams.

Open face window
window cut-out, also called a mortise, that has no covering. Our Boomerang #8 two-way mailer for quick printers has no patch in order to allow the printing of both the corner card and the return envelope in the same pass. Click here to see Boomerang #8.

Patch material – refers to the window covering material such as Polystyrene, Trycite (clear) or glassine (cloudy, hydroscopic and biodegradable).

Peel and Seal- adhesive which is exposed by peeling away a release strip, and which will then stick to just about anything. FedX pack, as an example.

– the degree of acidity or alkalinity measured on a scale of 0 to 14, with 1 being highly acidic, 7 being neutral, and 14 being highly alkaline.

Postage Meter Style – a window envelope oriented so that its window is located 7/8” left, ½” bottom but with the seal flap at the bottom of the envelope, rather than the top. Can be advantageous in some automatic Inserting machine applications.

Seams – the overlapping pieces of an envelope that hold it together. The alternative to seams is welded seams, wherein one sheet of paper is glued directly (welded) to the next. In this case the inside dimension of the envelope is foreshortened by 3/4” (3/8” on both ends).

Split seal gumming – refers to the practice of eliminating seal gum from that area of the seal flap that comes in contact with the diagonal seam that runs underneath it. At that point, because of the additional ply of paper created by the seam plus the seal flap, there is an increased tendency for the seal flaps to stick during storage. This is called tabbing, and can readily happen in areas of high humidity, or when the storage period is excessively long (a year or more).

Stamp ready – the seal gum is stopped short of the area where a postage stamp is placed in order to keep the seal flap from inadvertently tacking when the stamp is applied.

Tabbing- a visual/ physical way of keeping count by inserting a small paper tab at every 100th envelope. Adds a little to the cost per 1,000 envelopes. Banding, in qtys. from 8 to 50 is an option.

Throat - The distance between the seal flap fold line and the top of the back panel.

- Dupont’s Spunbonded Polyolefin that has become the standard material for wrapping houses, so there is no question about it’s durability or strength. It is so light that it can often save having to pay for an additional ounce of postage. However, it is difficult to fold or automatically insert as it lacks stiffness. Has a distinct TyvekR feel.

Vellum- a commodity grade paper which has the good folding characteristics of wove, but a toothier feel.

Wallet flap – a rectangular seal flap with either square or rounded corners.

Weatherproof paper - paper that is able to withstand water or very high humidity without dissolving or turning into mush. Examples are TyvekR and our Custom Laminate.

Wove – the most common grade of white paper used in envelope manufacturing. Smooth finish.

Watermark – a mark put in paper by a dandyroll when the paper is still wet on the wire or fourdrinier. Watermarks can be a design that belongs to the paper manufacturer or it can serve as the private logo of the company for whom the paper was made. “Strathmore 24 Rag Content” is a watermark familiar to many.


©2005 Sheppard Envelope