"Robert Allison" wrote in message
...

As others have said, T1-11 is plywood. It comes in 3/8" or 5/8"
thicknesses and either 4" or 8" wide options.

Here they offer an additional option to the 4 & 8" O.C. grooves, they offer
it with a 12" O.C.

They also offer it in yellow pine, or fir, with fir being more expense.

24 years ago, I finished my place with 5/8", 8" O.C. fir. I have stained it
twice. It still looks fantastic.