Board Backed Envelopes

Our Board Backed Envelopes (also known as rigid board back envelopes, hard backed mailers, or "Do Not Bend" envelopes) are purpose-built for UK businesses, online sellers, artists, photographers, and professional services to deliver robust, affordable protection for flat or semi-rigid items that must remain crease-free and undamaged during postal or courier transit.

Constructed with a strong grey board backing laminated to a durable 120gsm manilla or kraft paper front, these envelopes provide exceptional resistance to bending, crushing, folding, and impacts—far outperforming standard paper or padded envelopes for sensitive contents.

Key features and benefits include:

• Outstanding rigid protection — The solid board back prevents flexing, creasing, or damage from rough handling, automated sorting, conveyor systems, or multi-drop journeys, making them ideal for photos, prints, artwork, certificates, important documents, brochures, catalogues, greeting cards, or thin calendars that need to arrive pristine.
• Royal Mail Large Letter optimisation — Popular sizes are designed to fit within Royal Mail Large Letter limits (max 353 × 250 × 25mm, up to 750g), enabling lower letter-rate postage instead of parcel fees—crucial for cost control on platforms like eBay, Etsy, Amazon, or your own site. Common options include C5 (229 × 162mm for A5 or folded A4), C4 (324 × 229mm for full A4 sheets), and slightly undersized variants like 352 × 249mm or 324 × 229mm to maximise savings while often qualifying as Large Letter rather than Small Parcel.
• Versatile for everyday UK mailing — Perfect for sending A5 cards, A4 documents/artwork, A3 prints (in larger C3 sizes like 457 × 324mm), photographs, certificates, legal papers, or marketing materials. Many feature a shallow gusset or expandable design (up to 20–45mm) to accommodate slight thickness variations without compromising the flat profile.
• Simple and efficient packing — Supplied flat for space-efficient storage; quick to load with peel-and-seal adhesive strips (self-adhesive/hot-melt) for fast, secure, tape-free closure in busy fulfilment centres, offices, or home-based operations. Often include easy-open tear strips or rip tabs for customer convenience and a smooth unboxing experience.
• Professional "Please Do Not Bend" branding — Printed with prominent red "Please Do Not Bend" warnings on the front to alert handlers; available in natural manilla brown (traditional and eco-friendly look) or bright white finishes for a clean, premium appearance.
• Eco-friendly and sustainable — Made from responsibly sourced, fully recyclable materials (frequently with post-consumer recycled content in the board and paper), aligning with UK sustainability goals and helping your business reduce environmental impact without sacrificing durability.
• Reliable carrier performance — Compatible with major UK services including Royal Mail (Large Letter or Small Parcel tiers), Parcelforce, Evri, DPD, Yodel, UPS, and DHL—minimising damage risks, claims, or returns.

Best suited for non-fragile, flat items requiring bend resistance, such as documents, prints, and photos. For bulkier books, greater thickness, or enhanced cushioning needs, explore our book mailer envelopes, rigid boxes, or custom options.

Choose our board backed envelopes for dependable, low-cost packaging that safeguards important items, optimises postage savings, streamlines your dispatch process, and ensures a professional delivery.