I designed a right angle bracket that I intend to use in pairs. Due to its triangular shape, and the fact that my software creates rectangular rafts, it would be quite wasteful to print them individually.
I am not sure if STL files are supposed to contain more than one object. CoCreate seems to think so but ArtOfIllusion not. However, if you have a set of parts that go together to make one item then it would more convenient to store them in one file and print them together.
A simple workaround is to join all your parts together with an impossibly thin rectangle at base level.
The slice software samples at the middle height of each layer so this 0.1mm base gets missed out completely.
The down side is a bit more stringing as the head moves between the two objects.
These were made with 0.5mm filament through a 0.3mm nozzle and highlighted a problem. As you can see the top surface of the lower triangular part is rippled. The reason is that the filament is not being stretched much, if at all. That means that the sparse infill sags because it is not pulled taught. Three solid layers over the top is not enough to recover to flat as they are not being pulled tight either.
So it appears that some stretch is definitely needed unless you are making a solid object. Here is the same thing made with 0.4mm filament and all is well again.
The upper limit on filament diameter that is usable from a given size of nozzle is somewhat less than the die swell as you need to stretch it a bit.