In reference to the patent: US5769598
What exactly is protected with this patent number? Is it the exact design of the current "Don't stack" corrugated piece? Can the design be altered and not interfere with the Patent?
The Claims describe exactly what a patent covers. In most cases, the first claim is the most general.
In this case, the first claim says "A combination stacking damage detector and antistacking warning device, comprising:" and then lists four items.
If a new design did not satisfy all four of these items, then it would not be infringing.