Envelope MAILmedia C5 without window with patented closure technology

MAILmedia C5 envelope without window with patented closure technology is a plain C5-format envelope designed to hold A5 documents or A4 sheets folded once. The envelope combines a standard paper exterior with an engineered closure that improves sealing and tamper resistance during handling and transit. It is intended for everyday office, administrative and commercial correspondence where a secure, simple envelope solution is required.

Advantages

The patented closure technology provides consistent and reliable sealing without additional adhesives or tapes, reducing preparation time and minimizing the risk of accidental opening. The windowless design preserves document confidentiality and accommodates printed inserts, invoices and letters. The envelope’s size and material allow efficient stacking, storage and automated feeding in many mailing workflows.

Suitable for

• Mailing invoices and payment reminders
• Sending letters, contracts and administrative documents
• Distributing promotional inserts and folded brochures
• Office correspondence and bulk mailing operations

Key specifications

• Format: C5, suitable for A5 or A4 folded once
• Window: none (opaque)
• Closure: patented mechanical closure technology for secure sealing
• Material: paper envelope designed for standard mailing use
• Compatibility: compatible with manual and many automated mailing feeders

How to use

Insert the document or folded sheet into the envelope so that contents lie flat and do not exceed the envelope’s dimensions. Engage the patented closure according to the built-in mechanism — typically by aligning the flap and pressing along the closure area until it locks. Ensure edges are flush and verify the seal integrity before transporting or loading into mailing equipment. Do not overload the envelope or force bulky items through the closure.

Usage recommendations

For reliable results, use with standard-weight paper documents and avoid inserting thick card stock or multiple bulky pages. Store envelopes in a dry, room-temperature environment to preserve closure function and paper quality. When preparing bulk mailings, test the envelope and closure with your mailing equipment to confirm compatibility and feed performance.