Sharpie 37001 Ultra Fine Point Permanent Markers, Black (Box of 12) for $5.88. Shipping is free on orders over $25. If needed, use this Filler Tool to pad the order to qualify for free shipping. Here is a screenshot for your reference. It features 0.2mm narrowed tip with AP certified nontoxic fast drying, fade and water-resistant ink, and is permanent on most surfaces. Most places have it for about $8.