Posted on 4/29/2013 7:55 AM by Grace Jeffers
You pick up a highlighter to make some notes… Throw on a high visibility jacket for an evening run… Mark a page with a bright Post-It... See an orange caution cone on the highway. All these common objects are fluorescent. But have you ever stopped to think about what makes something fluoresce?
Fluorescent products are engineered to be seen. Fluorescence is a factor of light waves and how our eye perceives them. Molecules both absorb photons of light and reflect them back at particular wavelengths—this is what gives things the colors we see. Fluorescent colors take wavelenths of light energy in, but instead of merely reflecting them, they change them, immediately re-emitting them at a slightly longer wavelength. Fluorescence is different from phosphorescence because fluorescence re-emits light immediately, whereas phosphorescence emits the light over a longer period of time. Both are forms of photoluminescence.
In natural light, our eye does not perceive fluorescent materials as emitting light in and of themselves—they are seen as just a color. But under ultraviolet or black light, which is light emitted at wavelengths not normally visible to the eye, the fluorescent molecules become excited and do visibly “glow”. Anything that is “glow-in-the-dark”, though, where light is emitted over an extended period of time, is phosphorescent. So the sticky stars that kids put on their ceilings are phosphorescent, not fluorescent.
Photo courtesy Hannes Grobe
One of the common uses for fluorescent dyes is in safety signage and clothing. The first Safety Color Code Standard was created in 1945 at the request of the War Department. NEMA, the National Electrical Manufacturers Association, currently publishes the Safety Color Code, and it is approved and regulated by ANSI (the American National Standards Institute). ANSI Z535.1 outlines the standard for fluorescent colors--technical definitions (light emitted at what wavelength, as measured by spectrophotometers) and color tolerances (hue, value and chroma). Fluorescent colors need to fall within a certain range on the chart to be in compliance with ANSI Z535.1.
The most interesting fluorescent material on the market right now is AX Suede, a product of MatMarket. Their AX Cube line, a fluorescent polyester suede, is thick, supple and bright--the suede texture allows for more saturation in the dyeing process. AX Cube is the only suede on the market that passes the ANSI fluorescent color standards, their Neon Yellow and Neon Orange scoring well above the baseline numbers for luminescence. Neon Yellow also passes a second standard, AATCC 16-2004, that regulates “color fastness to 40 hour light fade”. Some commercial fluorescent colors are produced using AZO dyes—the chemicals in these particular dyes tend to break down and release toxic amines, and products using them are banned in the EU. AX Cube is AZO dye-free.
AX Suede; photo courtesy MatMarket
AX Suede is marrying safety color standards with designer style. Talk about being engineered to be seen—you can’t miss these fabulous bright fluorescent suedes!