I'm translating a paragraph that describes drug product packaging:
Packaging: From 50 g to 500 g in a transparent polyethylene bag (either double-wall or bag-in-bag).
Which would be the better choice: "double-wall", "bilayer" or "two-layer"? The meaning is, the polyethylene bag has two similar layers in order to ensure the safety of the product (alternatively, two single-wall bags could be used, hence "bag-in-bag").
Maybe all three options are okay? I'm looking for one that would sound more natural to native speakers.