This might not be a new idea but I remembered that whilst I was printing PETG at 240C, I had horrible delamination problems between layers and had to turn up to 250C to get reliable prints. So considering that we wanted to stack prints, I wondered why not use this to our advantage.
Here's a depiction of what I'm thinking:
This method really depends on how well you are able to control the hot end temperature, what temperature the material delaminates at and what material is used.
I've experimented with PETG and it shows promising results that we can reliably get stacked prints that can be split apart easily by hand.
Left print shows the bottom of visor 2 and the one next to it is the top of visor 1. The surface finish is quite good with minimal drooping of layers as the layer was fully supported with no separation distance between each band. This is only one test print but it could be possible to repeatably create stack prints that are easy to remove using this method. This method does vary from printer to printer and material to material so do be aware. If the temperature difference between normal printing temperature and delamination temperature is too great, you may need to make some compromises on certain layers so that the hotend can reach the target temperature quickly.
Currently, I haven’t yet seen a slicer implement a delamination layer operation but hopefully it will be added soon. There are workarounds with slicers like Cura but the effect may not function as well, due to how the nozzle takes time to change temperature.