Staedtler LumoColor Permanent Marker - Tokyo Pen Shop
Amazon.com : 6 Pieces Permanent Markers, Different Sizes Double-Ended Permanent Marker Pen, Ultra Fine Tip, Fine Tip and Chisel Tip (Black) : Office Products
Sharpie® Fine Point Permanent Marker | Michaels
Best Fine-Tip Permanent Markers for Artists – ARTnews.com