How do you make church pew cushions?

How do you make church pew cushions?

What kind of wood are church pews made of? Standard pew backs have 1″ high density polyurethane foam and seats are available in 3″ or 4″ high density foam options. Screws are anchored into the inner-frame, made of solid oak. All plywood used on our church pews is high quality fir and do not contain any particle board products.