The luminous process of absorbing and emitting light is a physical change. The principle of luminescence is the transition of photoions. 

The visible light is a gathering of photoions. When exposed to visible light, photoions will be stored in tiny cavities on the surface of glow in the dark particles. When the surroundings become dark or the light source is turned off, these stored photoions will be released, causing the material to emit light. 

As time passes, the material release less and less light until they are completely dark. Once all photoions are released, the glow ceases. The process can be repeated by exposing the material to light again.

GlowUp® powder is safe, non-toxic, non-radiation and eco-friendly. It has passed SVHC (European Standard) which has requirement of 248 chemical substance.

Glow in the dark powder has a lifespan of at least 15-20 years, because its luminescence process is a recyclable physical process.

After apply it into liquid mediums, the lifespan of final products depends on the quality of the medium.

For example, if the glow powder is mixed with the clear paint to make the glow paint, once the clear paint started peeling or yellowing after 5 years, the glowing layer is not as bright as before. So the lifespan of the glowing paint is only around 5 years.

Glow in the dark powder should be stored in a cool and dry place.

Luminous pigments are unaffected by UV radiation but highly susceptible to humidity. To maintain their efficacy, unused portions should be tightly sealed to prevent moisture absorption. (Moisture exposure will cause luminous pigments hydrolysis, to become whiten and clump together, resulting in a decrease or loss of luminescence.）

Luminous pigment exists as tiny particles, not a fine powder as flour. When mixed with a liquid medium, they remain a suspension in the medium rather than dissolving.

The particle size range that we can supply is 5-1700 micron. The three main categories are: Ultra fine of 5-15 micron, Regular of 20-80 micron, and Large particles of 100, 200, 500, 800 and 1700 microns. Except them, if other particle size is needed, we can do customization.

Granularity is the most important indication, which is closely related with the final application. According to the production way and the final product, choosing the most appropriate particle size can ensure the smooth production and also the suitable effect. For example, if to print patterns on T-shirt by screen printing with 200-250 mesh screen, 20-30 micron will be the most suitable type. It can go through the mesh and form a smooth touch surface.

The granularity of luminous pigments is commonly represented by the “Average Particle Size” (D50). It is a range, not a single value. For example D50 = 25~35 micron/μm. That means beyond this range, there are some other particles are smaller than 25 micron, and some are bigger than 35 micron.

For most products, D50 is enough to be referenced. But for some special applications, such as ultra-thin coating layer, fine fiber, ultra-small nozzle of spray gun, D90 and Dmax has to be checked carefully.

The brightness of glow-in-the-dark powder is low-level illumination and cannot replace lighting. For example, the brightness intensity of a ceiling lamp in a bedroom is about 300-800 candelas, while the luminous intensity of glow-in-the-dark powder is only about one-thousandth of that or even lower.

The brightness of glow-in-the-dark powder gradually decreases over time and does not stay constant.

Buyers often obtain information from the internet. The glowing duration frequently mentioned, such as 8-12 hours, typically refers to a fully charged state under complete darkness in laboratory conditions, based on the theoretical “visible light standard” (see DIN67510). Achieving this in real life is challenging. Factors such as ambient light, the intensity and duration of the charging light source, and individual perception can all influence the observed brightness. The best approach is for buyers to obtain samples for personal observation or test them in actual use to determine if they meet expectations.

Brightness data cannot fully represent the performance of glow-in-the-dark powder, as brightness is an extremely sensitive metric. Data obtained from testing can vary greatly depending on the precision of the measuring equipment. Furthermore, factors such as the testing operator’s technique and even the ambient temperature can significantly influence the results. Therefore, relying solely on data to distinguish the quality of glow-in-the-dark powder is not enough. Get samples, produce them into products, and observing the results is the most reliable method.