Each of our gusseted poly bags are made of 100% Low Density Polyethylene (LDPE) resin that meets FDA/USDA specifications. Side gussets expand easily to fit over bulky or irregular size objects. Tubular construction with a durable bottom seal make these bags the best on the market. Features superior clarity for showing the quality of products. All our low density bags meet the size and thickness requirements of Federal Specification A-A-3174.The thickness requirements as stated in the Federal Specifications are + or - 20%.In most cases our bags are -15 to -20 percent so if thickness is important for you, please go to a higher thickness. Can be heat sealed, tied, stapled or taped shut. Available on rolls where noted. Available in 4 Mil thickness. Bottom sealed bags have 1/8" to 1/4" bottom skirt . Call for custom quote for large buy quantity.