Amazon.com: SHARPIE Oil-Based Paint Marker, Medium Point, Aqua Blue, 1 Count - Great for Rock Painting : Office Products
Amazon.com: Acrylic Paint Pens Blue & Purple Tones 22 Assorted Pro Color Series Markers Set 0.7mm Extra Fine Tip for Rock Painting, Glass, Mugs, Wood, Metal, Canvas, Projects, Non Toxic, Waterbased, Quick