This twelve sided Market Umbrella suites our tables better than any other umbrella. It's wooden frame and brass hardware compliment our table. The fabric is a synthetic material called Sunbrella Olefin. It has the feel of denim, but it doesn't absorb moisture so it will not mildew like a cotton fabric. The Olefin is pocketed to fit over the wooden frame so it can be easily removed and washed in a washing machine.