Abstract: An expandable folder is provided which includes a front panel member, a rear panel member, and an expandable gusset which connects the panel members and forms the bottom and sides of the folder. Reinforcing means are provided upon critical or highly stressed locations to enhance the durability and useful life of the folder. Various types of reinforcement are provided about and, preferably, over the top of the gusset. The end portions of the gussets along the sides and, where applicable, the bottom, preferably have a width which is at least twice the width of the gusset folds. The outer surfaces of the inner front and rear panel members are also reinforced to strengthen the folder at least in the areas where the gusset is attached, and, for best results, on the entire outer surfaces of the panels.

Abstract: An expandable folder is provided which includes a front panel member, a rear panel member, and an expandable gusset which connects the panel members and forms the bottom and sides of the folder. Reinforcing means are provided upon critical or highly stressed locations to enhance the durability and useful life of the folder. Various types of reinforcement are provided about and, preferably, over the top of the gusset. The end portions of the gussets along the sides and, where applicable, the bottom, preferably have a width which is at least twice the width of the gusset folds. The outer surfaces of the inner front and rear panel members are also reinforced to strengthen the folder at least in the areas where the gusset is attached, and, for best results, on the entire outer surfaces of the panels.

Abstract: An expandable folder is provided which includes a front panel member, a rear panel member, and a gusset member which connects peripheral portions of the bottoms of the front and rear panel members and at least a portion of the sides of the panel members to form the expandable folder. The gusset member includes a sheet having a plurality of accordion-like folds, with terminal folds of the sheet being wider than the other folds, and the terminal folds are connected to the front and rear panel members to enhance the connection therebetween. The expandable folder further comprises interior reinforcing strips positioned along at least part of the connection between the gusset member and panel members peripheral portion for preventing separation of the front and rear panel members from the gusset member when the folder is used. Reinforcing strips may also be provided along the top or corners of the gusset member or on outer peripheral portions of the panel members.