Sharpie 1780478 Gel Highlighter, Fluorescent Yellow. Sharpie Gel Highlighters feature SmearBlock gel technology that provides total smear protection across pen, marker and inkjet inks. Perfect for highlighting, writing, doodling and drawing. Smear protection includes ballpoint, roller and gel pens. Highlighter marks won't bleed through paper and work on most paper surfaces, including glossy and thin papers, magazines and Bibles. Highlighters won't dry out if left uncapped. Sharpie Gel technology writes as long as a traditional pen-style highlighter. Gel stick conforms to your handwriting style. Twist bottom to advance gel stick.