Despite their simplicity, bags have been fundamental for the development of human civilization, as they allow people to easily collect loose materials such as berries or food grains, and to transport more items than could readily be carried in the hands. The word probably has its origins in the Norse word baggi, from the reconstructed Proto-Indo-European bʰak, but is also comparable to the Welsh baich (load, bundle), and the Greek βάσταγμα (bástagma, load).

Cheap disposable paper bags and plastic shopping bags are very common in the retail trade as a convenience for shoppers, and are often supplied by the shop for free or for a small fee. Customers may also take their own shopping bags to some shops.

Types and typical use of shopping bags vary by country:

In many European Union countries, plastic shopping bags are free and common into the 21st century, but their use is becoming less widespread, partly due to environmental legislation, which has led retailers to charge for single-use plastic shopping bags. Ireland, for example, imposed a dedicated plastic bag tax, thus forcing retailers offering plastic bags to charge for them.
Reusable shopping bags are increasingly used, e.g. in E.U. countries where use of single-use plastic shopping bags is in decline. Reusable bags are often made from jute cloth, also known as burlap in the U.S., but sometimes they are also made from plastic; however these reusable plastic bags are sturdier than single-use plastic shopping bags. In the U.S.

Metallisation is performed using a physical vapour deposition process. Aluminium is the most common metal used for deposition, but other metals such as nickel or chromium are also used. The metal is heated and evaporated under vacuum. This condenses on the cold polymer film, which is unwound near the metal vapour source.

This coating is much thinner than a metal foil could be made, in the range of 0.5 micrometres. This coating will not fade or discolour over time. While oriented polypropylene and polyethylene terephthalate (PET) are the most common films used for metallisation, nylon, polyethylene and cast polypropylene are also used.

Despite their simplicity, bags have been fundamental for the development of human civilization, as they allow people to easily collect loose materials such as berries or food grains, and to transport more items than could readily be carried in the hands. The word probably has its origins in the Norse word baggi, from the reconstructed Proto-Indo-European bʰak, but is also comparable to the Welsh baich (load, bundle), and the Greek βάσταγμα (bástagma, load).

Cheap disposable paper bags and plastic shopping bags are very common in the retail trade as a convenience for shoppers, and are often supplied by the shop for free or for a small fee. Customers may also take their own shopping bags to some shops.