Isn't gyroid infill just so cool? 

I made this model to show off how interesting the gyroid infill is. I also learned that it is very strong. Even at low infill percentages, it can still hold up a lot of weight. Also, if you look at it from one of its sides or the longest diagonal, there are these holes, and it just looks really cool.

I thought this would be easy, but it was harder than I thought. First, you have to set wall loops and top/bottom shell layers to zero. But you also have to set the "Maximum length of sparse infill anchor" to zero and turn off "Reduce infill retraction" so it has no stringing on the infill, or the whole print in this case.

This was harder than I thought, because at certain infill percentages, there are these huge overhangs that would normally be supported by the walls, which are nonexistent in this case. The first print profile is just 5% and 2.5% for the bigger one but the big one was not easy to get to work. Eventually I found that 1.5% worked for 180mm³ (max A1 mini size). It is possible to make it denser, but I have not messed with this -- yet. It is likely possible to make one that is possible to sit on, but that would be denser, and you wouldn't be able to see the pattern as well.

If you want to print a denser one, 2.48% seems to look pretty good w/ no giant overhangs.