This pack of 20 contains black HDPE plastic bubble mailers, 260×300 mm outer size, with a 40 mm sealing flap. Black gives the packaging a discreet, professional appearance. For webshop owners and craftspeople who need colourful, waterproof packaging.
What is in the pack of 20
The pack contains 20 black HDPE bubble mailers. Outer size: 260×300 mm, plus a 40 mm sealing flap at the top. The inner bubble lining is fused to the outer HDPE plastic layer, creating a sealed, air-cushioned surface that protects the contents. The mailers arrive stacked flat.
Material and bubble lining
The outer layer is HDPE (high-density polyethylene) plastic in a black colour — it is important to note that this is not a biodegradable material, but conventional long-life plastic. The black colour comes from pigment blended into the material itself, not from a surface coating, so it will not rub off. HDPE is waterproof and the inner air-bubble layer (around 6 mm thick) provides shock protection. As an eco-friendlier alternative, kraft paper or PBAT/PLA biodegradable mailers are available within the same family.
Size and use cases
The 260×300 mm outer size is suitable for medium-to-large shipments: larger books, thin tools, a two-piece cosmetic set, thicker clothing (T-shirt, hat), or A4-sized brochure packs. The 40 mm sealing flap provides enough room to close the mailer securely without compressing the contents. It is suitable for daily webshop fulfilment, posting handmade goods, or sending sample shipments to small businesss. The coloured exterior is also practical: it is easy to distinguish from brown cartons and the customer recognises the packaging immediately.
Closure system and opening
A strong self-adhesive strip runs along the top of the mailer, covered by a release liner. After removing the liner, fold the flap onto the back and press it down — the adhesive bonds instantly. The recipient finds a small tear notch at the edge of the flap from which the sealed section can be torn open easily. The mailer is single-use sealing: once opened, it cannot be safely resealed, which also functions as a tamper-evident indicator.
Storage and durability
Store the mailers in a dry, cool place away from direct sunlight, in their original packaging or a closed box. Storing them flat and stacked prevents the bubble lining from being deformed. Prolonged UV exposure may cause the black colour to fade over time. The adhesive strip is preserved for years at room temperature (15–25 °C); below −10 °C let the mailers reach room temperature before posting.