BIC™ Marking® Retractable Permanent Marker conveniently retracts with just one click! It has bold, long-lasting color and a durable fine point tip. Seal Guard Defends Against Dry Out®. These markers mark on just about everything: glass, metal, plastic, photos, foils and coated paper as well as oily and damp surfaces. Low-odor, acid-free ink (no added acid; no measurable pH). Marker Ink Type: Permanent; Marker Tip Type: Bullet; Marker Tip Size (text): Fine; Marker Color(s): Black.