Containerboard Price Index

What Is Containerboard?

Containerboard is the broad term for the paperboard grades used to manufacture corrugated boxes. It encompasses two primary components: linerboard (the flat facing sheets on the outside and inside of a corrugated box) and corrugating medium (the fluted sheet sandwiched between the liners). Together, these materials are combined on a corrugator machine to produce corrugated board, which is then die-cut and printed into finished shipping containers.

Why Containerboard Prices Matter

Containerboard is the single largest cost input in corrugated box manufacturing, typically accounting for 50% to 65% of the total cost of a finished box. When containerboard prices rise, box plants pass those increases through to end customers, often within 60 to 90 days. For large-volume box buyers, even a $20-per-ton increase in linerboard can add meaningful cost when multiplied across millions of square feet of corrugated board consumed annually.

Reading These Two Indexes

The Corrugated Shipping Containers index (PCU32221132221102) reflects the price of the finished product — the assembled, printed, and shipped box as sold by the box plant to the end user. The Corrugated Sheets and Rolls index (PCU32221132221105) tracks the intermediate product — corrugated board in sheet or roll form that is sold to independent sheet plants or converters who fabricate their own boxes.

When the Sheets and Rolls index rises ahead of the Containers index, it often signals that raw material costs are climbing and finished box price increases are forthcoming. When both indexes move in lockstep, it suggests that cost pass-throughs are working efficiently. When they diverge — particularly if the Containers index lags — it may indicate competitive pressure among box makers that is compressing conversion margins.

Market Structure Context

The U.S. containerboard market is highly consolidated. The top four producers — International Paper, WestRock (now part of Smurfit WestRock), Packaging Corporation of America, and Georgia-Pacific — control roughly 70% of domestic capacity. This concentration means that published price increases from the major mills tend to set the direction for the entire market, though actual transaction prices can vary based on volume commitments, contract terms, and regional supply conditions.