Demand for corrugated products and cardboard is down as consumer spend shows signs of slowing, leading big-box retailers to buy less and U.S. paper mills to scale back.

Shipments of empty boxes in March were down 11% from a year earlier, according to a Bloomberg report.

Indiana-based paper products maker and recycler Integrity Fiber Supply’s commodity trader Kyle Risinger said manufacturing is down because inflation is curbing consumer spending, hurting demand, Bloomberg reported.

“When things are good and everything is running solidly, the mills are running at about 90% to 92%, making paper and packaging,” Risinger said according to Bloomberg. “Right now, since the beginning of the year, they’re about 70% capacity.”