01Packaging buying guides

How to specify dimensions, board and inserts for corrugated mailer boxes

A buyer-friendly structure brief for corrugated mailer boxes, from product footprint to board construction and paper inserts.

4 Aug 2026Foshan Kehong Paper Products Co., Ltd. Editorial TeamNews & Insights

Corrugated mailer cartons prepared for dispatch

A mailer brief should connect the product footprint, board construction, closure and insert—not list them in isolation.

Direct answer

The short answer

Specify a corrugated mailer from the packed product outward: record the product footprint, clearance, closure, board or flute information, and any paper insert or divider. Review the insert with the closed box, not as a separate item. If board protection or the final structure is still open, request a structure review instead of assuming a fixed performance level.

Buyer comparison

Buyer comparison table
ElementRecordReview together with
Packed productFootprint, clearance and directionInner cavity and closure
Board constructionConfirmed board or flutePrint and converting route
InsertFold, fit and attachmentClosed mailer and packing sequence

Begin with the packed product

Measure the packed product, not only the product itself. Note fragile edges, accessories, clearance and the direction in which the item enters the mailer. Those facts shape the internal footprint and the closure sequence.

If several items share a box, include the arrangement and whether the buyer wants a paper insert, divider or simple wrap. A quick sketch can be more useful than a long description.

Describe the board construction

Use the board or flute information already confirmed for the project and distinguish it from the outer paper appearance. If the board specification is still open, ask for a structure review rather than assuming a fixed protection level.

The outside print area, inside print preference and closure method should be noted alongside the board. This keeps artwork, converting and packing discussions connected.

Review inserts with the structure

Paper inserts can keep a product positioned, separate components or create a presentation layer. Their dimensions, folds and attachment method should be reviewed with the mailer, because an insert that looks correct alone may not fit the closed box.

Share a product sample or reference image when available. The final brief should record the approved dimensions, board, insert and packing sequence before artwork moves to a dieline.

Before you send the brief

  • Packed product dimensions
  • Clearance and fragile points
  • Confirmed board or open structure question
  • Insert, divider or wrap preference
  • Artwork and packing sequence

Sources

中文版本: 瓦楞邮寄盒如何确认尺寸、纸板和内托