Indestructible Large Book & Poster Mailer The Lil A4 is a large book and poster cardboard mailer, built for delivering clothing, large books, cook books, puzzles, paintings, arts and craft materials, posters, maps, calendars and other large, flat items through the postal system. Manufactured using E flute corrugated cardboard with specially designed folds that provide impact protection around the edges, minimising the risk of damage in transit. The envelope features our leading peel'n'seal / tear strip system for easy sealing and opening. At 400 x 278mm flat, the A4 sits outside Royal Mail's large letter limit, so it ships under the small parcel tariff both flat packed and expanded. That's the trade-off for the extra capacity, this size is built for bigger, bulkier items where large letter compliance isn't the priority, protection and room to fit the product properly is. All products within our envelope range are made from 100% recycled material and are 100% recyclable. The Lil envelopes are the most eco-friendly, plastic-free alternative to a standard padded envelope or bubble mailer, and represent a significant step forward in the removal of single use plastics from ecommerce packaging. Padded envelopes stuffed with post-consumer recycled fibre actually use more material than our envelopes and are considerably slower to pack, yet don't provide any additional protection or cost savings. The corner stiffness of the A4 envelope cuts damage in transit, online retailers report nearly 70% fewer returns and 25% faster packing versus bubble mailers. The easy stack design also solves storage space problems for busy fulfilment operations. This range was developed alongside one of the internet's largest retailers, so you might recognise it. Explore the wider corrugated envelope range for other flat pack sizes. Lil Packaging is Europe's largest independent producer of cardboard envelope mailers, trusted by 10,000+ brands. Why Choose Our A4 Large Book & Poster Mailer Handles the larger items: clothing, large books, cook books, puzzles, paintings, posters, maps and calendars in one flat pack size Built for capacity: expands to 320 x 198 x 80mm, the deepest expansion in the A-range, for bulkier items that need more than a slim envelope Genuinely tougher: E-flute corrugated cardboard with reinforced folds outperforms padded envelopes and bubble mailers on protection, not just price Space saving: easy stack, flat pack design solves storage headaches for busy fulfilment operations Genuinely sustainable: FSC certified, Plastic Free and Zero Carbon as standard Proven at scale: developed alongside one of the internet's largest retailers Product Specification Size: 400 x 278mm flat, expands to 320 x 198 x 80mm Material: E flute corrugated cardboard, approx 1.5mm thick Closure: Tamper evident peel and seal (permanent bond) Postal fit: Royal Mail small parcel tariff, both flat packed and expanded (exceeds the large letter size limit) Certifications: FSC certified, Plastic Free, Zero Carbon
