A rigid (also called “set-up”) box is a container produced and delivered in three-dimensional form, ready to be filled. What distinguishes it from a folding carton is that it does not collapse like a folding carton, the chipboard used is up to four times thicker than a folding carton, and unlike folding cartons, printing is rarely applied to the board, but rather to a separate wrap (usually composed of paper, leather, or fabric) that is then adhered to a plain box.
Even though this package usually provides upscale details and construction, the rigid box can be manufactured without expensive dies or massive machinery, so converters have more leeway to plan and customize these packages to suit the product. For instance, production runs can be small or large, and production volume can ebb and flow, without resulting in excessive added expenditures. The rigid box also easily incorporates unique features and finishes, such as windows, domes, embossing, platforms, hinges, lids, and compartments. This adaptability is key in meeting a client’s need for quality, quantity, and expediency.
For more than 150 years, rigid boxes have been successfully employed in merchandising jewelry, cosmetics, and high-end couture. Consider Chanel, Tiffany, Hermès, Lanvin—their signature rigid box packaging has remained virtually unchanged for the past century. However, being so strongly associated with luxury has caused some some designers to overlook the benefits of a rigid box: that it provides superior protection, lends itself to sets or multiples, is easy to open and close, excels in stacking, handling, and display, and functions well as a reusable keepsake.
How a Rigid Box is Made
The process of creating a rigid box is fairly simple. It starts with non-bending chipboard and a simple steel rule die which, for a rigid box tray, contains knives (black lines) for cutting out the tray shape from the chipboard, and cut scores (red lines) that partially penetrate the board, allowing bending (scoring) without tearing. Vat-lined chip (chipboard lined on either one or both sides with a white coating made from newsprint, giving the box a more finished appearance) also works well for instances where the interior of the box is unfinished or unlined.
Next, ¾”-wide adhesive-backed tape is applied to the four corners of the tray on a machine called a quad stayer, to provide added stability.
Not all box wraps require printing, but along with foil stamping, embossing, debossing, or other decorative techniques, the corners of all rigid box wraps must first be trimmed or “mitred” so that when the box is formed, the wrap makes a perfect transition from two-dimensional blank to three-dimensional box.
A wrap can be adhered to a tray either tightly or loosely. A tight wrap applies adhesive to the entire back surface of the wrap while a loose wrap is generally only spot-glued at the edges of a lid, leaving the top panel without adhesive. The purpose is primarily aesthetic: a box made with a loose wrap appears to be handmade, and therefore more expensive. When much of the production was done by hand, loose wraps were more common but in today’s automated environment, loose wraps are only a small percentage of total production.
In an automated environment, the wraps, adhesive-side up, move along a conveyor where an operator carefully (and quickly) places the tray on the glued surface of the wrap. From there, the box moves to the right toward the wrapping station. Arms then grab the tray and pull it at a right angle into the wrapper. A plunger pushes the lid or base down and the adhesive-laden wrap is rolled up and over the tray, gluing it to the sides and inside lip of the box, giving it a turned edge.