When broaching the subject of interleaving and stacking, asking folks about the current state of affairs in this much ignored process there was less discussion about equipment systems and technical issues and more talk about costs — labor and packaging.
There’s no slight intended toward interleaving and stacking with the earlier characterization, but the subject does not get a lot of media attention. To those in the patty-processing business, the processes are as crucial as vacuum shrink bags and modified-atmosphere packaging are to whole muscle and case-ready suppliers, respectively. It’s simply that the exposure of interleaving and stacking has yet to achieve the “marquee” status others enjoy.
According to one processor, today, interleaving and stacking are more or less driven by two key decision factors. 
He chooses roll stock film as his primary package for frozen patties, because it is more cost-effective than cartons, another popular option. In fact, he estimates his per-package costs run about one-third less with roll stock.
He then added that the disparity would grow when the inventory space for various carton sizes was factored into his costs. Then, as if an afterthought and not to pile on, he remembered shrink film as yet another cost of packaging patties in cartons.
The second decision concerns loading. This processor’s volume is not at a level to warrant investing in automated loading equipment. He loads by hand. Even so, he estimates his labor costs would be at least double if he were using cartons instead.
Apparently, the versatility of roll stock packaging fits hand-in-glove with his combination of retail and foodservice business. Printed roll stock for his two, four-ounce burgers retail package delivers the distinctive graphics and case appeal he needs, while clear film works perfectly for two- and five-pound packages in the more utilitarian foodservice environment. In fact, he confidently pointed out, with roll stock, he can make whatever size package his customers need.
I was not sure what to expect or where my discussion would go around interleaving and stacking. Nuts and bolts, conveying and throughput would not have surprised me. Where it ended up going demonstrates that the industry’s thinking remains where it has been for a very long time: Get the right product in the right package at the right cost to deliver the right value.