Envelope B4 (250x353x40) brown with fold

B4 Envelope (250x353x40) Brown with Gusset – Capacity and Maximum Security

When sending thick contracts, catalogs, books, or other bulky documents, standard flat envelopes often tear or deform. The B4 format gusseted envelope is a professional solution designed to bridge the gap between a regular envelope and a shipping box. We tested this model and evaluated its practicality in logistics and office workflows.

Technical Summary (Specifications)

• Format: B4 (designed for larger than A4 formats).
• Dimensions: 250 x 353 x 40 mm.
• Paper Type: Brown kraft (130 g/m²).
• Closure: Peel and seal.
• Quantity: 250 units per pack.
• Extra Feature: Windowless, with gusset (expansion).

1. Exceptional Capacity with a 40 mm Gusset

The main advantage of this envelope is the special side and bottom gusset (expansion), which allows the envelope to expand up to 4 cm. This provides extra volume, making it:

• Flexible: Easily adapts to the thickness of the content while maintaining a neat shape.
• Versatile: Perfectly fits not only B4 sheets but also larger A4 document folders or thick files.
• Secure: The gusset reduces tension on the seams, making the shipment less prone to tearing during transit.

2. Durable Kraft Paper and Protection

The envelopes are made from 130 g/m² brown kraft paper. This density ensures the content is protected from external factors and guarantees confidentiality (the paper is opaque). Kraft paper has higher tensile strength than regular writing paper, making it a reliable choice for courier shipments.

3. Efficient Closure Mechanism (HK)

Time in the office is precious, so these envelopes feature a peel and seal strip (HK closure). This is extremely convenient because:

• No need to moisten the adhesive layer.
• The adhesive remains strong and tacky for a long time thanks to the protective strip.
• Sealing happens instantly, ensuring a tight and strong bond.

Verdict

This B4 gusseted envelope is an indispensable tool for law firms, logistics centers, and e-shops. It is a high-quality shipping package that ensures your correspondence reaches the recipient in a presentable and undamaged state. The economical pack of 250 units guarantees the best price-to-quality ratio for professional use.

Frequently Asked Questions (FAQ)

Will a thick A4 catalog fit in this envelope?

Yes, the B4 format is larger than A4, and the 40 mm gusset allows you to insert even a very thick catalog or several hundred sheets of paper.

Is the envelope suitable for parcel lockers?

Absolutely. Due to its durability and adjustable volume, it is ideal for securely sending documents or small goods via postal and courier services.