Capacity Book Mailers
Capacity Book Mailers
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£0.40 inc. VAT each
Product Information
Product Information
Our capacity book mailers are gusseted to provide the flexibility of a small postal box once loaded, making them ideal for shipping flat and delicate items securely. These envelope-style mailers are rigid, puncture-resistant, and designed to protect goods such as books, magazines, diaries, hardbacks, DVDs, CDs, Blu-rays, gaming discs and other similar products.
Each mailer features a super-strong peel & seal adhesive strip for quick, tape-free closure, plus a customer-friendly ripper strip for a clean and easy opening experience. Supplied flat-packed, these mailers save space in storage and are a dependable choice for e-commerce fulfilment.
We offer two strength options across this range:
- Premium Corrugated (micro F flute): medium to heavy duty protection with added rigidity
- Standard Solid Board (400gsm): light to medium duty protection with a slim, sturdy profile
Pricing in Proportion (PiP) Sizes
All of our capacity book mailers can be identified using Royal Mail’s Pricing in Proportion (PiP) index. Depending on the size and how much the gusset is expanded, these mailers fall into either the Large Letter or Small Parcel categories.
Key Benefits
- Gusseted design: expands up to 40mm to act like a small postal box
- Fast packing: peel & seal strip for secure closure with no tape required
- Easy opening: built-in ripper strip for a neat customer unboxing
- Recycled & recyclable: responsibly sourced board options
- Ideal for flat items: protects against bends, knocks, and punctures
Premium Corrugated Capacity Book Mailers – Size Guide
-
Size 1 (W x L): 180x235mm / 18x23.5cm
- Load Dimensions (W x L x H): 140x195x40mm / 14x19.5x4cm
- PiP Size When Flat: Large Letter
- PiP Size When Expanded: Small Parcel
- Kite Packaging equivalent: CFM180235M
- Our SKU: BOOK180-PC, MCP-BOOK180-PC-PSUK & MCP-BOOK180-PC
-
Size 2 (W x L): 194x292mm / 19.4x29.2cm
- Load Dimensions (W x L x H): 154x252x40mm / 15.4x25.2x4cm
- PiP Size When Flat: Large Letter
- PiP Size When Expanded: Small Parcel
- Kite Packaging equivalent: CFM194292
- Our SKU: BOOK194-PC, MCP-BOOK194-PC-PSUK & MCP-BOOK194-PC
-
Size 3 (W x L): 234x334mm / 23.4x33.4cm
- Load Dimensions (W x L x H): 194x294x40mm / 19.4x29.4x4cm
- PiP Size When Flat: Large Letter
- PiP Size When Expanded: Small Parcel
- Kite Packaging equivalent: CFM234334M
- Our SKU: BOOK234-PC, MCP-BOOK234-PC-PSUK & MCP-BOOK234-PC
-
Size 4 (W x L): 249x352mm / 24.9x35.2cm
- Load Dimensions (W x L x H): 209x312x40mm / 20.9x31.2x4cm
- PiP Size When Flat: Large Letter
- PiP Size When Expanded: Small Parcel
- Kite Packaging equivalent: CFM248345M
- Our SKU: BOOK249-PC, MCP-BOOK249-PC-PSUK & MCP-BOOK249-PC
-
Size 5 (W x L): 278x400mm / 27.8x40cm
- Load Dimensions (W x L x H): 238x360x40mm / 23.8x36x4cm
- PiP Size When Flat: Small Parcel
- PiP Size When Expanded: Small Parcel
- Kite Packaging equivalent: CFM278400M
- Our SKU: BOOK278-PC, MCP-BOOK278-PC-PSUK & MCP-BOOK278-PC
Standard Solid Board Capacity Book Mailers – Size Guide
-
Size 1 (W x L): 180x235mm / 18x23.5cm
- Load Dimensions (W x L x H): 140x195x40mm / 14x19.5x4cm
- PiP Size When Flat: Large Letter
- PiP Size When Expanded: Small Parcel
- Kite Packaging equivalent: CSB140X40X195
- Our SKU: CBM-2, MCP-CBM-2-PSUK & MCP-CBM-2
-
Size 2 (W x L): 194x292mm / 19.4x29.2cm
- Load Dimensions (W x L x H): 154x252x40mm / 15.4x25.2x4cm
- PiP Size When Flat: Large Letter
- PiP Size When Expanded: Small Parcel
- Kite Packaging equivalent: CSB154X40X252
- Our SKU: CBM-3, MCP-CBM-3-PSUK & MCP-CBM-3
-
Size 3 (W x L): 234x334mm / 23.4x33.4cm
- Load Dimensions (W x L x H): 194x294x40mm / 19.4x29.4x4cm
- PiP Size When Flat: Large Letter
- PiP Size When Expanded: Small Parcel
- Kite Packaging equivalent: CSB194X40X294
- Our SKU: CBM-4, MCP-CBM-4-PSUK & MCP-CBM-4
-
Size 4 (W x L): 249x352mm / 24.9x35.2cm
- Load Dimensions (W x L x H): 209x312x40mm / 20.9x31.2x4cm
- PiP Size When Flat: Large Letter
- PiP Size When Fully Expanded: Small Parcel
- Kite Packaging equivalent: CSB209X40X312
- Our SKU: SB-CE249, MCP-SB-CE249-PSUK & MCP-SB-CE249
-
Size 5 (W x L): 278x400mm / 27.8x40cm
- Load Dimensions (W x L x H): 238x360x40mm / 23.8x36x4cm
- PiP Size When Flat: Small Parcel
- PiP Size When Expanded: Small Parcel
- Kite Packaging equivalent: CSB238X40X360
- Our SKU: CBM-5, MCP-CBM-5-PSUK & MCP-CBM-5
Please note: Dimensions may vary slightly (±10–20mm) due to manufacturing tolerances. A sample service is available for testing prior to bulk orders. Branding/barcodes may appear on parts of the capacity book mailer. Images are for reference purposes only and there may be slight variances to the product supplied.
Fast UK Delivery
Fast UK Delivery
All of our products are manufactured and dispatched right here in our own UK warehouse, which means we can offer some of the fastest turnaround times in the country. And because everything is produced in the UK (unlike many other providers), you’ll never have to worry about customs delays or surprise charges. Delivery is calculated at checkout based on order value - free over £100, from £6.95 under that or select Next Day delivery upgrade for only £9.95. All orders are shipped flat-packed for maximum efficiency.
Product Reviews
Product Reviews
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Frequently Asked Questions
What sizes are available?
This range is available in five sizes - 180 x 235mm, 194 x 292mm, 234 x 334mm, 249 x 352mm and 278 x 400mm - in either Standard Solid Board or Premium Corrugated.
What's the difference between Standard Solid Board and Premium Corrugated?
Standard Solid Board is 400gsm and offers light to medium duty protection, while Premium Corrugated uses a micro F flute for medium to heavy duty protection and added rigidity.
What Royal Mail PiP band do these mailers fall into?
Depending on size, most mailers fall into the Large Letter band when flat and Small Parcel once expanded, though the 278 x 400mm size is Small Parcel in both states.
How much can the mailer expand to hold contents?
Each mailer is gusseted and scored to expand up to 40mm, giving it the flexibility of a small postal box once loaded.
How do I close these mailers?
They feature a super-strong peel and seal adhesive strip for tape-free closure, plus a built-in ripper strip for easy opening.
What items can I send in these mailers?
They're ideal for books, magazines, diaries, hardbacks, DVDs, CDs, Blu-rays and gaming discs, and are despatched the same working day when ordered before our cut-off.
Why Choose Us
Free UK Delivery Available
Choose from a few delivery options including FREE delivery to mainland UK on orders over £100.
Trusted Supplier
Over 20 years’ experience in the postal industry under Mailcoms Ltd.
UK Based
All products are printed and made in the heart of England, keeping our carbon footprint as low as possible.
