Envelopes and delivery bags: formats, closures and protection

An envelope can take in a business letter, an invitation or a small commodity. The appropriate selection is based on content, desired presentation and protection requirements. Format, paper quality and closure are independent properties.

Which format fits the paper?

Cover	Measure	Typical content
C6	114 × 162 mm	A6 card or twice folded A4 sheet.
C5	162 × 229 mm	A5 sheet or once folded A4 sheet.
C4	229 × 324 mm	A4 without folding.
DL	110 × 220 mm	A4 letter with matching third fold.

These format examples are also used in the Materials of the Deutsche Post In this context, it is important to note that: Multiple hands, thick cards or deposits require extra space. A matching paper format does not automatically mean that each stack fits in.

Type of closure

In case of an adhesive cover, a cover strip is removed and the flap is pressed. Self-adhesive variants can have two prepared adhesive surfaces depending on the design. Wet-adhesive envelopes require the intended humidification. Note storage and manufacturer’s instructions, because an old or dirty adhesive tape can hold worse.

Paper and design

Surface weight, surface and color influence the impression and processing. A stronger paper can make an invitation look more valuable. Visibility is important for confidential documents. A window envelope saves the separate address if the address and folding of the document match exactly to the window position.

Before applying a printed application, check whether the envelope and printing process fit together. A decorative colour or a large logo shall not affect the legibility of the shipping information. For unusual forms and thick content, the conditions of the chosen shipping service must be examined separately.

If more protection is needed

• A paper envelope protects a letter from immediate insight, but offers little shock protection.
• Cardboard delivery bags can stabilize flat content against creases.
• Air cushion covers cushion smaller items, but do not prevent any pressure load.
• Reinforced paper and multilayer bags can be practical for suitable goods.
• Film bags are flexible and can protect surfaces from moisture; they are not a rigid protective cover.

A sample copy is worth it

Insert the actual content, close the envelope and check edges, thickness and address area. A too full envelope loads the closure and can tear open at the seams. For fragile items, a small, padded box is often the more appropriate solution. The decisive factor is the complete protective structure, not the decorative name of the envelope.