{"product_id":"custom-printed-mailer-postal-boxes-375x255x150mm","title":"Customised Printed Mailer Postal Boxes - 375x255x150mm","description":"\u003ch2 class=\"producth2\"\u003eFull-Colour Personalised 375x255x150mm Mailer Boxes\u003c\/h2\u003e\n\u003cp\u003eGive your packaging the professional edge with our custom printed 375x255x150mm mailer boxes. These popular postal boxes are ideal for shipping clothing, gifts, eCommerce orders, and subscription sets, offering a secure, premium unboxing experience that keeps your products protected and your branding front and centre.\u003c\/p\u003e\n\u003cp\u003eManufactured from sturdy corrugated kraft board, these mailer boxes combine strength with a smooth surface that’s perfect for vibrant full-colour digital print. The triple-layer construction adds durability for dependable shipping, while the clean kraft finish ensures your packaging looks sharp and consistent across every order.\u003c\/p\u003e\n\u003cp\u003eEach box is supplied flat-packed to save storage space and assembles quickly using strong folding tabs and flaps. Designed to qualify as a Royal Mail Small Parcel size, these mailer boxes help you avoid failed deliveries and keep postage costs predictable - making them a practical, brand-boosting solution for busy fulfilment environments.\u003c\/p\u003e\n\u003cul class=\"productbullets\"\u003e\n\u003cli\u003e\n\u003cspan class=\"bold\"\u003eVibrant full-colour print:\u003c\/span\u003e Add your logo, artwork or message in crisp digital colour for instant brand recognition.\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"bold\"\u003eRoyal Mail Small Parcel friendly:\u003c\/span\u003e The 375x255x150mm internal size is designed to fall within Royal Mail’s Small Parcel category.\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"bold\"\u003eStrong mailer-style protection:\u003c\/span\u003e Triple-layer corrugated kraft board gives reliable strength for posting a wide range of products.\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"bold\"\u003eProfessional unboxing feel:\u003c\/span\u003e A smooth kraft surface and clean structure help elevate presentation for retail and subscription orders.\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"bold\"\u003eSupplied flat-packed:\u003c\/span\u003e Saves valuable storage space and keeps your packing area tidy.\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"bold\"\u003eQuick, secure assembly:\u003c\/span\u003e Folding tabs and flaps lock firmly into place for a tamper-resistant seal.\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"bold\"\u003ePrinted proof \u0026amp; satisfaction guarantee:\u003c\/span\u003e Approve a full printed sample of your 375x255x150mm mailer box before full production.*\u003cbr\u003e\u003cspan class=\"font10\"\u003e*Please note this excludes printed single sample orders.\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"bold\"\u003eFast UK turnaround:\u003c\/span\u003e Printed and delivered in as little as a few days to keep orders moving.\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"bold\"\u003eUK made \u0026amp; printed:\u003c\/span\u003e Manufactured and printed in the UK to reduce transport mileage and carbon footprint.\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"bold\"\u003eFSC® certified materials:\u003c\/span\u003e Produced using responsibly sourced board with 60%–90% recycled content.\u003c\/li\u003e\n\u003cli\u003e\n\u003cspan class=\"bold\"\u003eSize guide:\u003c\/span\u003e Small parcel mailer postal box sizes (375x255x150mm) shown are the internal dimensions: \u003cspan class=\"bold\"\u003eWidth x Depth x Height\u003c\/span\u003e.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch3 class=\"producth3\"\u003eConsidering a printed sample?\u003c\/h3\u003e\n\u003cp\u003eWe offer an optional printed sample so you can confirm colour quality, print sharpness and suitability before ordering in larger quantities. When you proceed with a full order of the same design, we will refund the cost of the sample.\u003c\/p\u003e\n\u003cp\u003e\u003cspan class=\"bold\"\u003ePlease note:\u003c\/span\u003e Minor branding or barcodes may appear on parts of the 375x255x150mm mailer boxes. Images shown are for guidance only and the supplied product may differ slightly.\u003c\/p\u003e\n\u003cp\u003e\u003cspan class=\"bold\"\u003eDue to manufacturing tolerances, actual item dimensions may vary by 10–20mm. If sizing accuracy is essential, we recommend ordering a sample before placing a larger order.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch3 class=\"producth3\"\u003eAuthentic Product Photography\u003c\/h3\u003e\n\u003cp\u003eAll images displayed on Parcelsend UK represent genuine printed jobs we have produced. No visuals on this page are created or enhanced using AI - every photograph is taken from real customer orders to give you an honest representation of print quality and finish.\u003c\/p\u003e\u003cdiv id=\"zakeke-product-tag\" style=\"display:none\" data-product-id=\"15234541912439\" data-enviroment=\"Customizer\"\u003e\u003c\/div\u003e","brand":"Parcelsend UK","offers":[{"title":"White E-Flute \/ Outside Top Only","offer_id":56154823262583,"sku":"MCP-PIP375WH-RM-POT-PSUK","price":3.37,"currency_code":"GBP","in_stock":true},{"title":"White E-Flute \/ Outside Front Flap Only","offer_id":56154823295351,"sku":"MCP-PIP375WH-RM-POF-PSUK","price":3.37,"currency_code":"GBP","in_stock":true},{"title":"White E-Flute \/ Inside Only","offer_id":56154823328119,"sku":"MCP-PIP375WH-RM-PI-PSUK","price":3.37,"currency_code":"GBP","in_stock":true},{"title":"White E-Flute \/ Outside Top \u0026 Outside Front Flap","offer_id":56154823360887,"sku":"MCP-PIP375WH-RM-POTF-PSUK","price":4.3,"currency_code":"GBP","in_stock":true},{"title":"White E-Flute \/ Outside Top \u0026 Inside","offer_id":56154823393655,"sku":"MCP-PIP375WH-RM-POTI-PSUK","price":4.3,"currency_code":"GBP","in_stock":true},{"title":"White E-Flute \/ Outside Front Flap \u0026 Inside","offer_id":56154823426423,"sku":"MCP-PIP375WH-RM-POFI-PSUK","price":4.3,"currency_code":"GBP","in_stock":true},{"title":"Brown \/ Kraft E-Flute \/ Outside Top Only","offer_id":56154823459191,"sku":"MCP-BSPB-13-POT-PSUK","price":2.3,"currency_code":"GBP","in_stock":true},{"title":"Brown \/ Kraft E-Flute \/ Outside Front Flap Only","offer_id":56154823491959,"sku":"MCP-BSPB-13-POF-PSUK","price":2.3,"currency_code":"GBP","in_stock":true},{"title":"Brown \/ Kraft E-Flute \/ Inside Only","offer_id":56154823524727,"sku":"MCP-BSPB-13-PI-PSUK","price":2.3,"currency_code":"GBP","in_stock":true},{"title":"Brown \/ Kraft E-Flute \/ Outside Top \u0026 Outside Front Flap","offer_id":56154823557495,"sku":"MCP-BSPB-13-POTF-PSUK","price":2.94,"currency_code":"GBP","in_stock":true},{"title":"Brown \/ Kraft E-Flute \/ Outside Top \u0026 Inside","offer_id":56154823590263,"sku":"MCP-BSPB-13-POTI-PSUK","price":2.94,"currency_code":"GBP","in_stock":true},{"title":"Brown \/ Kraft E-Flute \/ Outside Front Flap \u0026 Inside","offer_id":56154823623031,"sku":"MCP-BSPB-13-POFI-PSUK","price":2.94,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0437\/0094\/5064\/files\/customised-printed-mailer-boxes-375x255x150mm-mixed.jpg?v=1763565245","url":"https:\/\/parcelsend.uk\/products\/custom-printed-mailer-postal-boxes-375x255x150mm","provider":"Parcelsend UK","version":"1.0","type":"link"}