i would think pointy sides up and down would make the space look taller, flat sides up and down would make the space look wider.

Can't help you with technical, sorry, but your question made me curious, so I searched and found them installed both ways. Here's two with points up!

thx barncatz there didn't seem to be any reason why you couldnt, but I have learned to also seek advice when doing something new. Like maybe you cant really cut the the little pieces you'll need for the top and bottom without serious chipping. You just never know what is lurking to mess up your "Easy" project.

The only reason it matters is to minimize having to make difficult tiny cuts. I usually layout the hex sheets on the floor and use tape measure to see what the cuts look like one way vs. the other. Try to land in the 'meaty' center of the tile if at all possible.

Just remember if your choice means the layout of the tile sheets are at any angle other than 90 degree it is significantly more labor intensive and will require cuts and more sheets of tile to complete your look.