Inspired by the colors of nature, Graf von Faber-Castell inks are carefully formulated with the highest-quality ingredients for smooth ink flow. They also resist drying out in the pen, so you can pause for thought and start writing again immediately without hard starts breaking your concentration. Document proofed: smudge-resistant, reproducible, light-fast and waterproof, cannot be erased and is resistant to many chemicals and solvents. Highest-quality ingredients. Even flow of ink. Elegant ink glass.