What is Glow In The Dark stuff?
Also Known as Luminous, Luminescent, Photoluminescent stuff.
Materials that light without need of any external power source, no electrical connections at all.
How does it work?
Exposure to light causes a chemical change in the material, in the dark the material returns to its original state and the energy released excites phosphors that give off light, very like a rechargeable battery.
Is it Radioactive?
Clock and instrument dials up to the late 20th century were coated using radioactive Radium based luminous paint, this is no longer used.
Tritium vials such as Traser are mildly radioactive and do not require exposure to light to glow, the sources are very small.
Strontium Aluminate activated with Europium is what modern photoluminescent materials are made from, this is non radioactive and non toxic.
Glow in Dark stuff used to fade after 10 minutes , is this better?
Zinc Sulphide was the Glow in Dark pigment used for many years in low cost applications, it has a very short afterglow.
Strontium Aluminate pigments are far better, brighter initial glow and far longer, by hours after glow.
Intial glow is quite strong and after long exposure , will still be visible in a dark environment for 10+ hours after.
What is the Brightest Colour?
Light green glow is the the brightest initial and longest after glow.
In pigments Blue is next brightest but significantly dimmer, violet is dim but long glowing, Red has a very short glow time.
How long does it continue to work for?
Our photoluminescent products are made using industrial quality materials, some of our products have been in place for 10 years now. You can confidently expect to be glowing for many years.
Can you `switch` them off?
A caution where using them for stage guidance or other areas where a persistent glow may be distracting, you can not just switch off photoluminescent material , it will remain glowing.
You can draw on photoluminescent material with a white or UV flashlight to leave a bright trail.
A Red laser pointer will switch off, non permanently darken, a narrow line of Glow in Dark material.
Photoluminescent , Chemiluminescent, Electroluminescent , Fluorescent , whats the difference?
Photoluminescent is` glow in the dark`, glows after exposure to light, requires no power beyond initial charge and is reusable thousands of times.
Chemiluminescent is seen in Lightsticks , break and shake like Cyalume, gives out light from chemical reaction , brighter than Photoluminescent but one time use.
Electroluminescent , EL Wire , thin, typically 3 - 6 mm, electrically powered glowing wire, light output similar to chemiluminescent , dimmable and controllable, life span of few thousand hours.
Fluorescent as seen in Blacklight reactive and `neon ` material colours, not self glowing but glow in a visible colour in presence of invsible UV blacklight.