Custom size boxes, quoted to your inside dimensions

Why measure inside

Boxes are specified and ordered by inside dimensions, because the inside is what has to fit the product. The outside size depends on the board: double wall is thicker than single wall, so the same inside size has a bigger outside. Length is always the longer side of the opening, width the shorter, and depth runs from the opening to the floor of the box.

Add room for whatever protects the product: an inch of foam or air pillows on every side adds two inches to each dimension. Then round to the nearest eighth or quarter inch.

Overruns and underruns

Corrugated is made in runs, and a custom run can come off the line slightly over or under the count ordered. This is normal in the trade. If you need an exact number, say so on the quote and ask what tolerance applies.

When stock will do

If a stock size is within half an inch of what you need on every side, the stock box may be quicker and cost less. Send us the size either way; we will tell you if a common size is close enough.

Who orders custom sizes

Furniture makers with flat-pack panels, instrument and equipment builders, food brands with an unusual jar, sellers of framed prints, and parts distributors replacing a carton the original supplier discontinued. Most began with a stock box that did not quite fit, measured what they needed, and found the custom run cost less than they expected once damage and void fill were counted.

Ordering more than one size

Shippers with a family of products often end up with several close sizes. Before ordering each, check whether two could merge into one with an insert or a little padding. Fewer sizes means larger runs, simpler storage and fewer packing mistakes. Send the whole list and we will point out any likely merges.

From measurement to box

Once the inside size, style and board are set, the plant works out the blank size, the score positions and the flap lengths. For an RSC that is routine; for a die-cut, someone draws the blank and a die is made. A sample box may be cut first to check fit. You approve the size, and then the run is scheduled.

Tips for a good fit

Test-pack a product in a mock-up made from an existing box cut down to size, or from foam board, before committing. Leave room for the closing tape and any inserts. Remember the box will be slightly smaller inside once the flaps fold in, especially with thick double wall. For several similar products, a single size with inserts can be cheaper than several sizes.

When to choose it

• Products that rattle in the nearest stock size.
• Parcels where dimensional weight is costing you.
• Cases that must fit a palletizer pattern exactly.