This 20-piece pack contains black HDPE bubble mailers with a 180×230 mm outer size and a 40 mm sealing flap. The outer layer is black HDPE plastic that provides a discreet, exclusive appearance and water-resistant protection. The inner layer is an HDPE-based bubble film that uses small air pockets to absorb impacts during transit. The pack is intended for webshop owners, craftspeople and small businesses who ship mid-sized, flat or boxed items.
What is included in the 20-piece pack
The pack contains 20 black HDPE bubble mailers, each in 180×230 mm outer size with a 40 mm sealing flap. The total gross weight is approximately 0.33 kg, around 15 g per unit — providing a particularly favourable postal cost for mid-sized shipments. The 20-piece quantity offers several weeks of basic cover for a small-to-medium webshop or a permanent home stock for a craft brand.
Material and bubble lining
The outer layer of the envelope is black HDPE plastic — a robust, fundamentally water-resistant polymer that does not let through drizzle or warehouse humidity. The black colour gives the parcel a discreet, modern look: the contents cannot be seen from outside and the mailer conveys a clean visual message. The inside is an HDPE-based bubble film, with a cushioning layer of small air pockets around the contents.
Size and use cases
The 180×230 mm outer size is well suited to mid-sized shipments: a smaller book or notebook, an A5 document, a boxed cosmetic (cream set, gift box), a smaller garment such as a scarf, an electronics accessory (cable, USB device in a box), or several smaller items together. The 40 mm flap leaves room for a clean seal.
Closure and opening
The inside of the flap carries a self-adhesive strip that can be sealed in a single motion once the protective tape is removed. The envelope gets a secure, tamper-evident closure: the recipient can only access the contents by tearing the flap, so any reopening is visible. The black plastic layer is opaque — the contents are not visible from outside.
Storage and shelf life
Store the envelopes in a dry, cool place, away from direct sunlight. The UV resistance of HDPE plastic is good, but for prolonged sun exposure it is worth keeping the stock in a closed drawer or cabinet. The adhesive strip's protective tape typically retains full tack for 12 to 18 months from production — rotating your stock continuously is recommended so that you always work with fresh adhesive.