Material for square false bottom

Hey guys,
I just got a 16gal square cooler to turn into a lauter turn. I bought a round false bottom but it will not fit. I saw somewhere on the internet, but can not find it again, a cooler just like mine with a metal peice with holes that was perfect for the false bottom. But I dont know what kind of material it was. Does anyone know the picture and website of which I saw mabe. Or does anyone have an idea of what it could have been?
thanks

www.onlinemetals.com carries perforated stainless. That's what I made mine out of.

Round Hole Stainless Perforated Sheet 304
Dimensions
Dimension Name Value
Thickness 0.036"
Hole Size 0.0625"
Stagger 0.125"

$47 for a 12x24" sheet seems so steep to me. This is exactly why I chose to batch sparge using a 18" stainless braid.

I used the size thinner than that with slightly larger holes, Bobby:

Thickness 0.03"
Hole Size 0.09375"
Stagger 0.15625"

It's quite a bit cheaper and is exactly the same material as the domed false bottoms from More Beer. I paid a little over $30 for a custom cut of 14"x17."

thanks for the fast posts guys. Ill look into it, see if Lows has it or Home Depot. I already have a plastic false bottom for a circular cooler but cant find a 10 gal one only a 5gal one. Any ideas?
thanks

Look at the false bottom in the cooler in my gallery. I got the plastic sheeting at a hobby store for $1.50 It works excellent.