[whitehse]

I believe I remember looking at the foul line many times at Comiskey and realizing it wasn't just a chalk line but an embedded "line" of some type set into the ground. I do remember the grounds crew taking a pain bucket and a rather large brush and going up and down the line painting the foul line. I always wondered what that foul line was made of and I guess I now know!!

Edited to add the foul line I am speaking of was only in the outfield....the infield was still chalked as it has been for years. The outfield had a permanent foul line which is what I think the OP is showing here.