The Pigmented Ink Is Both Acid-Free And Archival (Ph Neutral). Smudge-Proof And Waterproof When Dry. The Ink Contains The Highest Quality Pigments For Unsurpassed Lightfastness. Superfine, Fine, Medium, And Brush Tip – Black Ink Is Acid-Free And Archival (Ph Neutral). Smudge-Proof And Waterproof When Dry. Unsurpassed Lightfastness

