a bag made of paper or plastic for holding customer's purchasesA paper bag is a bag made of paper, usually kraft paper. Paper bags can be made either with virgin or recycled fibres to meet customers' demands. Paper bags are commonly used as shopping carrier bags and for packaging of some consumer goods.A paper bag or paper sack is a preformed container made of paper, usually with an opening at one end. It can be one layer of paper or multiple layers of paper and other flexible materials. Paper bags are used for packaging and/or carrying items.Standard brown paper bags are made from kraft paper. Tote-style paper carrier bags, such as those often used by department stores or as gift bags, can be made from any kind of paper, and come in any color. There are two different styles of handles for paper carrier bags: flat handles and cord handles. Paper carrier bags made from virgin kraft paper are developed especially for demanding packaging. Paper bags can be made from recycled paper, with some local laws requiring bags to have a minimum percentage of post-consumer recycled content.[12]

Paper bags can be made to withstand more pressure or weight than plastic bags do. While brown is the color of the most common type of paper bag (brown being the natural color of the wood fibre), this pair of words connotes more than just the color.

The verb form of brown bag, depending on content, may be an act of civil disobedience (and illegal)[19] or an action by 60 million American brown baggers whom a marketing research study's review by the New York Times described as upscale.[20]

The former refers to lack of a liquor license, whereas the latter are for particularly those on vegetarian, low-salt, low-cholesterol or kosher diets.

The noun form of the term included in the Merriam-Webster dictionary in 1950 refers to use of a paper bag instead of a lunch box. William Safire traces this to an article in Time magazine.

When the content is solid food, it may be preserved or enhanced before being consumed because a substantial minority of brown baggers have access to microwave ovens or refrigerators.[20]