Pressed Cotton sells gray-washed wooden chalkboard boxes, from $19 each, that can be filled with plants or flowers and used as centerpieces. Have the boxes do double duty by using chalk to write table numbers on the side.
Photo: Courtesy of Pressed Cotton
Also available through Pressed Cotton are chalkboard tags, $3.50 each, which can be used as signage or place cards or can be hung from the neck of wine bottles to designate tables.