How to Spec ECT and Board Grade for Export Cartons

Quick answer

Specify export cartons from the load and stacking case outward: carton ID, gross weight, stack height, distribution conditions, flute/board construction, and minimum ECT. An ECT number without those conditions is not a reliable export-carton specification.

Start with the packed product

Give the supplier packed gross weight, internal dimensions, product support pattern, and whether the product carries any stacking load. A dense product in an oversized carton can fail even when the board grade looks high.

Translate the transport route

State palletized or floor-loaded shipment, container duration, humid-season exposure, warehouse stack height, and whether the carton enters parcel distribution. Container stacking and parcel drops create different failure modes.

Choose a board construction

Single-wall B or C flute suits many export shippers; E flute favors print and smaller packs; double-wall is for higher loads or longer stacks. Name flute combination and liner/medium weights where the plant uses them.

Set ECT as a minimum

Ask for a minimum finished-board ECT, not a nominal paper grade only. Confirm the test method, conditioning basis, and whether the quoted ECT applies to production board rather than a lab-development sample.

Protect against moisture loss

Compression falls when board absorbs moisture. For humid lanes, use a practical safety margin, protect pallets from wet floors, and avoid assuming dry-lab ECT equals container performance.

Validate the converting

Board grade cannot compensate for weak glue joints, poor score depth, excessive die-cut perforation, or a carton packed above its intended height. Inspect production samples after conversion.

RFQ

Carton style; ID L×W×H; packed gross weight

Flute/board construction; minimum finished-board ECT

Stack pattern/height; route; humidity or parcel exposure

Print; joint type; sample and compression-test requirement

Related PackTrades Knowledge

Corrugated Board ECT and FCT Explained, Why Export Cartons Crush in Container Stacks, What Is Flute Combination in Corrugated Board?, RSC and Heavy-Duty Corrugated Boxes from China.