Conductive Silver Ink Pen - Micro Tip [CW2200MTP] : ID 515 : $59.95 : Adafruit Industries, Unique & fun DIY electronics and kits
Conductive Ink Paint Pen - Black or Gold — PMD Way
Circuit Scribe Conductive Ink Pen at School Outfitters
Circuit Scribe Non-Toxic Conductive Ink Pen for Kids Circuit Building Set | Silver Ink Rollerball Point Pen for Circuit Scribe Kit, Science Experiment, DIY Science Projects | Single Pack : Toys & Games - Amazon.com