Description
When your items demand extra width and protection beyond standard sizes, our 444 × 368 mm board backed envelopes deliver premium hard backed envelope strength and flatness. Built with 950 µm stiff board and a 115 gsm paper shell, these mailers are tough enough to handle postal handling while maintaining structure. This listing is for bulk quantities, perfect for high-volume users such as print houses, designers, galleries, art sellers, or any business sending large flat items regularly.
Features & Construction
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Dimensions: Internal size 444 mm × 368 mm (approx 17.4″ × 14.4″) — ideal for items that don’t neatly fall into standard envelope sizes.
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Materials: Strong backing board (950 µm) combined with a 115 gsm paper shell, for durability and rigidity.
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Peel & Seal Closure: Quick, tamper-resistant closure for efficient packing.
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“Please Do Not Bend” Warning: Printed in red on the front to signal careful handling.
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Weight: Each board backed envelope (empty) weighs around 125.5 g.
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Bulk Packs Available: Options include 50, 100, 250, 500, and 1,000 units (or more) to suit business usage
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Free UK Shipping (over certain orders): Many orders qualify for free UK mainland delivery.
What Fits Inside & Use Cases
With its generous width and height, this mailer is ideal for shipping:
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Oversized artwork, illustrations, or posters that exceed standard formats
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Panoramic prints or pieces with wide orientation
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Multi-sheet presentations or portfolios, laid flat
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Large mounted prints or framed pieces (thin mount)
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Specialty marketing packs, sample boards, or foldouts
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Legal documents, plans or blueprints that require more horizontal space
Because of the rigid board core, your items will arrive flat, free from creases, bends, or postal damage.
Why You Should Buy in Bulk
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Lower per-unit cost — prices drop significantly when buying larger quantities
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Consistent stock for frequent use — never run short when demand is high
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Quality consistency — every envelope meets the same rigid standards
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Efficient for packing & fulfilment — bulk formats streamline storage and dispatch
Key Benefits & Selling Points
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Robust protection — the thick board backing prevents bending even under stress
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Professional finish — flat, undamaged items create a strong brand impression
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Non-standard advantage — this size handles wide formats that other envelopes can’t
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Business scale ready — bulk packaging and consistency support commercial mailing
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Handling clarity — “Please Do Not Bend” message helps reduce mishandling in transit
