Credit to Lumanieri on Printables https://www.printables.com/model/92346-door-stacker-system-stack-rack/files

I've been painting the doors at my house and I originally saw this type of thing on Amazon but I wanted to find an alternative that I could print. Found this item on Printables and will be printing it out of PLA. Could probably be good with 10-20% infill unless you want them to be a lot stronger if you are stacking more than a couple doors.

Files include documentation, along with GCODE provided by the creator and the STL's. The size of these are fairly large and may need to be sized down but I don't know how much that will affect the usage of them. Your mileage may vary.