The versatile Uni Pi:s markers (pronounced like "piece") are double-sided with an extra fine tip on one end and a fine tip of the other. Their oil-based ink writes on practically everything, including paper, plastic, glass, metal, and more! Even when you write quickly, lines stay solid and pigmented. Whether you're using them for writing or drawing, you can have a pleasant experience as their tips are made of fibers that don't make unpleasant noise. Eco-friendly, with a body made from recycled materials, these markers are part of Uni's Green-Net brand, which features products that minimize damage to our environment.