What is too thin to print?

I’ve noticed that many times the printer ignores certain parts of my design if it is too thin. My question is, what is too thin? Can I go below half a mm?

The extrusion width needs to be at least as large as layer height in order to be constrained enough to form a predictable path. Depending on the material and shape, you may need a much wider extrusion to get acceptable layer bonding.

Cura often seems to ignore walls thinner than 0.5mm.

I’ve noticed that Cura ignores 0.5mm thin walls in my prints. Slic3r doesn’t ignore those however and will print them. I like the simplicity of Cura, but sometimes, you have to use a different tool when it falls down.