The 2 main interior surfaces I've heard of is flat white paint and Mylar. My plants have outgrown my tent and I have changed closets so my main walk in closet is empty. It's already a flat white but I was thinking of lining the closet walls with mirror tile. Do you think it would create hot spots or work better??
I did a lot of reading before painting my rooms and found the consensus to be that mirrors were bad for reflecting light... I ended up using the kool seal elastomeric roof coating from Walmart and absolutely love it It reflects wonderfully and is very easy to wipe clean.... Worth checking out...
I think mirrors only reflect 30% of useful light or something shitty like that. Flat white paint or some reflective mylar is the way to go. I use flat white poster board for my space - easy to set up, move around and cheap. If you have white walls just work the corner.