SENATOR LIBERTY BIO BALL PEN. Popular Senator Liberty Ball Pen, Now Available in a Modern Version Made of Biobased Plastic. Made From Renewable Raw Materials, Durable & Biodegradable. Perfect Ambassador for Your Environmentally Conscious Brand Presentation. Available in Natural, Corn Yellow, Orange, Tulip Red, Pale Green, Natural Green, Rich Blue, Fresh Blue, Warm Grey 3, Warm Grey 10. Minimum Quantity: 500.