Most listings show black poly mailers made from polyethylene; one listing specifies polypropylene.
Common closures include self-adhesive (self-seal) strips and peel-and-seal designs. Some listings also include a perforated tear strip for easier opening.
Mailer surfaces are described as accepting adhesive shipping labels and direct writing with permanent markers or pens. One listing explicitly notes that labels, stamps and ink adhere well.
Descriptions cite tear-resistant engineering, puncture resistance and strong seams designed to withstand rough handling and overpacking.
The listed pack or item weights vary in the provided product details, ranging from as light as 0.88 ounces up to 20.5 ounces.