This 25-piece pack contains kraft bubble mailers with a 285×370 mm outer size and a 40 mm sealing flap. The outer layer is robust kraft paper and the inner layer is an HDPE-based bubble film that absorbs impacts during transit. The envelopes in this size are specifically intended for webshop owners, craftspeople and small businesses who ship larger-than-A4 items that are still relatively flat or not too thick, and who want a packaging with a considered look.
What is included in the 25-piece pack
The pack contains 25 kraft bubble mailers, each in 285×370 mm outer size with a 40 mm sealing flap. The total gross weight is approximately 1.65 kg, which provides several weeks of cover for a higher-volume webshop, or a comfortable buffer stock for a larger craft market. The net weight per unit is around 60 g, so the envelopes do not push your shipments unnecessarily into a higher postal weight class.
Material and bubble lining
The outer layer is made of kraft paper whose natural brown tone immediately sets it apart from conventional plastic mailers and gives a customer-friendly, mindful impression. The inside is an HDPE-based bubble film that forms a cushioning layer of small air pockets around the contents. This combination pairs a paper-like external surface with serious mechanical protection — the bubble lining is particularly good at absorbing the pressure and vibration that occur during postal transit.
Size and use cases
The 285×370 mm outer size comfortably fits a folder larger than A4, a photo album, a mid-sized book, a flat garment such as a T-shirt or scarf, or several smaller items packed together. The 40 mm flap leaves room for a clean seal, so you do not have to fill the envelope all the way to the edge and the contents are not pressed against the adhesive strip.
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. This gives the receiver feedback that the parcel arrived in its original state.
Storage and shelf life
Store the envelopes in a dry, cool place, away from direct sunlight, either flat or in light stacks. The adhesive strip's protective tape typically retains full tack for 12 to 18 months from production, so it is worth rotating your stock regularly. Moisture may soften the kraft layer, so storing directly on the floor is not recommended.