Where variation comes from
Board thickness varies slightly between sheets. Adhesive adds a fraction. A wrap folded around a corner takes up more on a thick material than a thin one. None of these is a fault; together they are why a wrapped box is not a machined part.
The tighter the interior fit, the more these add up, which is why a fitted seat is specified against the piece rather than against a number.
Interior against exterior
Only one of the two can be held tightly. If the interior must fit a piece exactly, the exterior floats by whatever the construction adds; if the exterior must fit a fixed outer carton or a mailer, the interior takes the variation.
Tell us which one matters and we hold that one. A brief that fixes both is a brief that cannot be met.
Where it actually matters
A ring slot that is a fraction tight marks the shank; a fraction loose and the ring turns. A watch cushion that is a fraction small will not take the clasp. Those are the places to spend the specification.
Exterior height on a gift box, by contrast, almost never matters to anyone.
Specifying to a mailer or a carton
Where the box has to fit inside something else, give us the inside dimensions of that thing rather than the outside dimensions you want the box to be. We work back from it, and that removes a whole class of error.
How it is checked
The approved pre-production sample is the reference and the run is measured against it, not against a drawing. That is deliberate: the sample is the thing you held and agreed, and it already contains whatever the construction adds.
At a glance
| Question | The answer |
|---|---|
| Can both interior and exterior be held tightly? | No — say which one matters |
| What sets the interior? | The actual piece, not a number |
| Fitting inside a mailer? | Give us the mailer's inside dimensions |
| What is the run checked against? | The pre-production sample you approved |
Frequently asked questions
How exact is made to size?
Close, with variation from board, adhesive and wrapping. A wrapped box is not a machined part, and the tighter the interior fit the more that matters.
Can you hold both the interior and the exterior exactly?
No. Tell us which one matters and we hold that one; the other takes the variation.
How do I specify a box to fit our mailer?
Send the mailer's inside dimensions. We work the box back from them rather than from a target exterior size.
What is the production run measured against?
The physical pre-production sample you approved, not the drawing.
Tell us what you need
Tell us the piece, your brand and the quantity you have in mind. We’ll send photos of our work and one clear, all-in quote.