Your Partner in Mailing and Packaging Solutions since 1930. Back in 1930, Calumet Carton was created as a small, family-owned manufacturer of folding cartons and rigid mailing envelopes to Chicago area companies. 80 years and four generations later, Calumet is still owned by the Inwood family, but has grown into the leading producer of mailers and packaging products, serving customers from coast to coast. Our stock line include the nationally known Stayflats® and Stayflats Plus® brand of rigid mailing envelopes, Stayflats Lite™ and Stayflats Utility™ lightweight rigid mailers, Expand-A-Mailer™ gusset envelopes and ConfirMailers™, Delivery and Signature Confirmation Mailing Boxes for USPS First- Class Mail® . The stock line also includes 42 sizes of Kraft reverse tuck folding cartons and white reverse tuck folding cartons. Calumet Carton is also a full service folding carton manufacturer. We specialize in designing and producing custom packaging to your exact specifications. This includes custom designed and printed folding cartons, mailers, point of purchase displays and small flute corrugated boxes. Calumet Carton is based in South Holland, Illinois located approximately 30 minutes south of Chicago.