I ordered a bicycle helmet that came in a box too fragile to send unwrapped (it had an open side where you could see the helmet). It’s too small, and I need to return it.
It came in a grayish-white heavy duty plastic (maybe Tyvek?) bag about 24" by 12". It had an adhesive strip that sealed it quite well, which I had to tear to open. A quick Google search reveals that these kind of bags are available from wholesalers in huge lots (like 1000). But where can I pick up just one? The USPS store seems to have smaller mailer bags with padding but I need something larger.
It’s essentially a big heavy duty bag, no liner, and went around the box snugly.
You might try an office supply store like Staples or Office Depot, or a pack/ship store like UPS stores. I can order them from my shipping supply vendor, but they only sell bulk quantities: www.uline.com.
Staples and the USPS only stock up to size #7 (14-1/2" x 19") which is gonna be way too small. You can get a box that would fit the helmet at either place for under $5.