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Parts of an Envelope

How many of these components of an envelope do you know?


Parts of an Envelope

Can you identify all the parts of an envelope?

Most of us use or handle envelopes everyday. But do you know how an envelope is constructed? The envelope you design or choose for your desktop publishing projects is just as important as what goes in it.

The size of the piece, type of mailing, budget, and whether or not you'll be using automated equipment to insert the envelope contents affects the style of envelope you can use. You can also choose specific envelope sizes and styles to enhance a personal or business image, invoke a particular action, or create a certain aura.

When discussing envelope options with clients and printers, basic knowledge of envelope construction can help you cut costs and choose the best envelope for the project.

Face or Front
The front of the envelope, usually seamless, may have windows that allow the inside contents to show through. The face of the envelope is where the address, postage, and usually the return address appear.

The back of the envelope, typically left blank, is where the flaps meet to form and seal the envelope.

The parts of an envelope that are folded, overlapped, and sealed to enclose the contents are typically rectangular or triangular with rounded, tapered, or pointed corners. The typical envelope consists of two side flaps, a bottom flap, and a top flap. The side flaps are folded in first with the bottom flap folded up. They are sealed where they overlap. The top flap is folded over the side and bottom flaps and sealed after inserting the envelope contents.

  • Top Flap
    Also known as the seal flap, it comes in four main styles: commercial, wallet, square, and pointed. There are variations to this basic flap style, such as some types of business reply or remittance envelopes that include a tear-off section on the flap.

  • Side Flap
    The sides of the envelope folded to the inside and sealed along the bottom flap form a pocket. Side flaps may be wide or narrow and rectangular or triangular in shape with straight or rounded corners.

  • Bottom Flap
    The bottom flap is folded up and sealed along the edges of the side flaps to form a pocket. It may be squarish or more triangular, depending on the style of envelope, with straight, rounded, or flattened corners.

The style of flaps determines the type of seams -- the edges where the envelope flaps meet and overlap.

  • Diagonal Seams
    Envelopes with pointed or triangular flaps create diagonal seams across the back of the envelope.

  • Side Seams
    Running close to the outer edge of the envelope, square or rectangular flaps form side seams.

  • Center Seam
    Found on catalog style envelopes, large square or rectangluar side flaps meet and overlap in the center of the envelope.

  • Seam Overlap
    That portion of the flaps that overlap to form the seams of the envelope.

The creases formed at the sides, top, and bottom between the face and the back when all the flaps are folded to the back of the envelope are the folds.

  • Top Fold
    Usually scored during manufacturing, the top flap crease is where the top flap is folded to seal the envelope.

  • Side Fold
    The side creases along the sides of the envelope separate the front or face of the envelope from the side flaps folded to the back.

  • Bottom Fold
    The crease along the bottom of the envelope separates the front or face of the envelope from the bottom flap.

Envelope Openings and Closures
Envelopes have one side left open and unsealed for inserting material. Non-square envelopes are either open end or open side. Open side is the most common, even though most letter mail envelopes appear to open on top. The opening is determined not by orientation of the top flap but by the length of the side where the opening appears. In addition to the style or position of the flap, envelope closures may be with or without adhesive. Other open areas, such as windows, are for viewing the contents without opening the envelope.

  • Throat
    The space between the top fold and top of the bottom flap that forms the opening where envelope contents are inserted.

  • Shoulder
    The shoulder is a portion of the side flaps along the throat where they meet the top fold.

  • Window
    Some envelopes have one or more cut-out areas, usually on the face of the envelope, so that a mailing address, return address, or special message shows through from the inside. Windows may be left open or might have a clear or tinted covering. Window envelopes can be custom-designed or purchased with window sizes and positions.

  • Open Side
    On rectangular envelopes, when the top flap (opening) is on the long side of the envelope, it is an open side.

  • Open End
    Open end envelopes have the top flap and opening on the short side of the envelope. Catalog envelopes are typically open end as are many specialty envelopes such as coin envelopes, policy envelopes, and some interoffice envelopes.

Put these components of an envelope together to form standard and custom envelopes in a variety of sizes.

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Tips & Tutorials:How to Do Desktop Publishing
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In the Classroom: Back to School With Desktop Publishing
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