All About BoxesThe BasicsWe have included this section to help you select the proper style and type of box to meet your packaging and shipping needs.MeasurementsBox sizes are measured by using inner dimensions unless otherwise specified. The size of your contents actually determine the inner box dimensions. Domestically (within the United States), those dimensions are listed in the following sequence: Length (L) x Width (W) x Depth (D)*. Internationally, the dimensions are stated as Length (L) x Breadth (B) x Height (H).Dimensions are based on the opening of an assembled box. Looking at the opening, the longer of the two sides is considered the length. The shorter of the two sides is the width. The side perpendicular to the length and width is the depth of the box.*Exceptions are bookfolds, bin boxes & divider bins where width precedes length & depth of the measurement sequence.How To Measure A Box - The Quick WayLooking at the opening of the box, measure the longest or length panel first. Using a tape measure, place it in the bottom of the box approximately one inch from the back wall and measure from left to right. Repeat the process for the shorter width panel. Then, folding a side flap inward until it is perpendicular to its vertical side wall, place the tape measure at the end of the flap and extend it downward until it rests on the inner flap at the bottom of the box (see illustration). This exercise will give you the depth dimension of the box.One-piece, die-cut boxes, such as the mailer-style with a tuck-in top, do not have flaps when assembled, but the measuring procedure is basically the same. For the box depth, use the inside back panel as it has a visible score line (crease separating back panel from lid). For the width of a die cut box, measure between the score lines found on the inside of the top or lid. And, of course, for the length of the box, place your measuring rule on the bottom of the box approximately one-inch from the back panel. Measure from left to right. Box Construction - What you need to knowThe Manufacturers Joint is where the two ends of the side panels meet to form the box. At that point, the panels are fastened together with tape, staples or glue. This description applies to regular slotted shipping cartons (RSCs). The side panel thickness and content weight determine the type of seal used for the manufacturers joint. For example, glue is used for most single wall boxes, but staples are found in some double wall and in most triple wall boxes. In contrast, die-cut boxes are one-piece panels scored and folded together. They do not have a manufacturers joint.Box StrengthThe strength of a corrugated box starts with its material. A corrugated sheet consists of two major components - linerboard and medium. Linerboard is the flat paper that covers both sides of the sheet and the medium is the fluted or arched paper found between both liners. The flute, when anchored to the linerboards with a starched-based adhesive, resists bending and pressure from all directions. When placed vertically on its ends, the flutes form vertical columns, capable of supporting considerable amounts of weight.Flutes come in five basic heights and shapes - the most common are B-Flute(used for die-cut boxes) and C-Flute (used for RSCs). B-flute is compressed and appears thinner, but dont be fooled. It is made with more paper to provide stronger side wall protection from blows and punctures. C-flute is taller, with more air space, but offers enhanced stacking strength. For excellent graphic reproduction, consider E-flute.The amount of virgin pulp fibers and the length of those fibers in a corrugated sheet substantially contribute to box strength. For example, the difference between a 200# test box and a 275# test box is that the latter has more pulp fibers in its corrugated linerboard. The 200# test box is rated to hold up to 65 lbs. of box and contents while the 275# box can hold up to 95 lbs. A 350# test box is rated to hold up to 120 lbs. of box and contents. The following chart shows Bursting Test and Edge Crush Test performance standards of corrugated box liners based on the combined weight of a box and its contents.Look for the Manufacturers StampA way to be sure that the material of the box that youre purchasing meets industry standards is to look for the Manufacturers Certification Stamp, usually printed on one of the bottom flaps of the box. The stamp identifies the material as singlewall, doublewall or triplewall. It also certifies the Mullen Bursting Test (most common is 200 lbs. per square inch) or the Edge Crush Test (ECT 32 lbs. per inch). The Mullen Test measures the bursting strength of the corrugated linerboard while the Edge Crush Test measures linerboard stacking strength. The 200 lbs. Mullen box and the 32 ECT box are comparable in stacking strength. But that is where the similarity ends. The Mullen Test box is bette