He looked at new ways of using other materials too.
It was always a risk, using human material like these.
I could have used material that I'd come up with before.
More than 20,000 schools, 60,000 teachers and about two million students use the materials.
"It seemed like a great idea to use the material again."
They also use different materials from those common in other parts of the world.
It was built between 1924 and 1925 using local materials.
The hall was built using materials from the local area.
"We will also be using material from other news organizations."
I had to be near the edge to use material like that.