The most basic wood pallet—the stringer pallet—is actually fairly lightweight, but it comes at the cost of being flimsy. Stringer pallets are made of half-inch thick boards nailed to three two-by-fours, and the boards can pull loose or break when handled by a forklift, and this can result in product damage. To better protect products during transport, the shipping industry started using a more robust block pallet. It uses nine four-by-four-inch blocks instead of stringers, adds more deck boards, and uses more nails to hold the pallet together. Block pallets are much sturdier than stringer pallets, but they have a trade-off: they weigh significantly more, and their weight can increase under certain environmental conditions. Wood is an absorbent material and wet wood block pallets can weigh up to 80 pounds. A 53-foot trailer holds about 26 pallets; block pallets may make up as much as 2,000 pounds of its weight—a full ton. If a trailer is cubed out and filled vertically, pallets may make up an even greater proportion of the weight of the load.
Shipping pallets are necessary to move and store products on their way to the retailer or end consumer, and supply chains would struggle to meet demand without them. However, unlike the products that pallets carry, pallets themselves cannot be sold for profit. Extra energy spent moving pallet weight is an additional cost that doesn’t offer a return. Reducing a shipment’s weight saves on the fuel costs needed to transport it, and reducing the portion of that weight that is attributed to pallets maximizes profits.