TECH stands for Technical! 12 colors made with fine artist’s pigments for transparent, lightfast, archival results! 🎨 . . Dr. Ph. Martin's TECH Drawing Ink is designed specifically for use with technical pens, calligraphy pens, and drawing pens. It also works well with brushes and airbrushes. TECH Drawing Ink is acid-free and waterproof. Ideal for design and illustration! #drphmartins