Whether you’re a packaging distributor who’s been in the business for years or a new online boutique looking for your first order of customized paper bags, using correct paper bag terminology is important. Knowing and using these terms will help you make smarter packaging decisions and maybe you’ll even impress your friends with some new trivia!

  1. Basis Weight. Basis weight is the weight in pounds per ream (500 sheets) in the basic measurement for a specific grade of paper. Often, basis weight describes the “weight” or thickness of the paper. Lightweight paper bags like food bags, merchandise bags, and pharmacy bags are made from basis weights ranging from 20# to 40#. In comparison, heavyweight hardware bags and shipping bags range from 57# to 126#. The higher the basis weight the thicker/heavier the paper is. Basis weight is not a measurement of paper strength only of weight.
  2. SOS Bag – also called a block bottom or square bottom bag. SOS bags are “lunch” style bags that stand up on their own when opened. They range in size and are often used for a variety of packaging purposes.
  3. Merchandise Bag – also called pinch bottom, or flat bags. Merchandise bags do not have a flat bottom and are manufactured with or without gussets.
  4. Gusset – an indented side fold of a paper bag allowing the bag to expand for larger items.
  5. MF (Machine Finish) / MG (Machine Glaze) – MF and MG describe the finish of paper. Most often, MG paper appears to have a glazed finish on one side and a rough finish on another. MF paper has a rough finish on both sides.
  6. Calendared / Supercalendared – The last operation on the drying machine before the paper is wound on reels. Machine calendars are stacks of vertical cast steel rolls that have polished ground surfaces. The paper enters the stack at the top and is compacted and smoothed progressively as it travels down the stack. This often replaces MG paper as it is smooth on both sides and offers an excellent printing surface.
  7. Tinted – also called Flood Coated. Bags that have 100% coverage of ink on one side of the paper (typically the outside of the bag). Tinting white or kraft paper creates a custom colored bag. WCI tints our Cream, Forest Green, and Wild Rose stock bags.
  8. Beater Dyed – paper dyed during the manufacturing process when the material is still a slurry. This creates paper that is a solid color all the way through the paper. If the bag is cut or ripped, the inside of the sheet or fiber is colored the same as the outside. Most WCI stock colored bags (except those listed above as tinted) are beater dyed colors.
  9. Post Printing – The process of printing on bags after they have already been produced. A finished bag that has already been formed and glued is run through a secondary operation where the print is added to the bag. Smaller businesses can take advantage of this option to create branded packaging in lower quantities. Because the bag has already been folded and glued, graphic size and placement is more limited when post printing.
  10. Inline Printing – The process of printing on the paper during the bag manufacturing process. At WCI this process is used for custom printed orders larger than 5,000 on standard sizes. Printing inline allows for greater flexibility in the number of colors and sides the bag can be printed and a larger print area because the print is added to the paper before the bag is formed.

Want to learn more about paper and printing terminology? Visit our glossary!