Fluorescent chalk — for outdoor work and high-contrast drawings
All of our chalk is heavily pigmented and reads vividly in normal light. Fluorescent is different because the pigments absorb ultraviolet light — from sunlight or a UV bulb — and re-emit it as visible light. The result is a color that looks noticeably brighter, almost self-lit, compared to a standard color next to it. Under full sun on concrete, the difference is dramatic.
Street painters use fluorescent chalk to make outdoor work hold up against bright pavement. Artists doing daytime presentations use it to pull specific elements forward. If you’ve ever seen a drawing where one figure seems to hover above the rest of the scene in daylight, it’s probably fluorescent pigment doing the work.
Black light chalk — for hidden images and reveals
Black light chalk is invisible under normal light. It only becomes visible when a UV black light bulb is shining on it. Gospel chalk artists have used it since the 1940s to draw a “hidden image” during a presentation — the artist draws the visible portion of the scene in standard chalk, and at the climactic moment the black light comes on, revealing a second image already drawn on the same surface in invisible chalk.
Dr. Karl Steele invented black light chalk in the early 1940s and debuted it at a meeting at the Maranatha Conference Center in Michigan, revealing a fire chariot at the translation of Elijah. Every hidden-image drawing done since is built on that technique.
