Where do you get that white grating?

[nicktreb]

I was a Lowes a few hours ago picking up some supplies for an incubator I am converting from an old Red Bull cooler.
While I was there I was trying to find that white grating stuff to use for a shelf in the incubator. I asked 3 different people working there and no one had any idea what I was talking about.
Does anyone know what that stuff is technically called? Has anyone been able to buy it from Home Depot or Lowes?

Find a good ceiling and rip it down.