As we all know, you cannot observe the color without the observing light source.
Between visible light at 390nm and 760nm, we introduce a physical concept representing the luminous color of the light--color temperature. The color temperature of the light source is shown when the light source shines, and its unit is the absolute temperature Kelvin "K". The higher the K value, the more the color of light tends to white and blue, that is, the more tends to 3900nm; the lower the K value, the more the color of light appears to yellow and red, so, the more tends to 760nm. As shown in the figure.
D65 light source (6500K color temperature) is a light source of slightly cooler color of the light body. In China, D65 is one of the standard color temperatures used in large quantities.
According to ISO3664:2000, the standard light source must meet two physical conditions:
1. The color temperature of the light source is D50 or D65
2. The rendering index of the light source Ra> 90
Ra is more closer to 100%, indicating that the color appearing by the light source is more closer to the color exposed by natural light.
According to the requirements of the International Organization for Standardization ISO (ISO3664:2000), in the printing industry,Standard Viewing Environment must be used to observe colors and make color matching.
So,what is Standard Viewing Environment for melamine decorative paper printing?
It refers to:
1. The light source must be a standard light source
2. Observe the illumination> 2000 Lu / + 500 Lu on the surface
3. The observed background environment must be neutral ash
In the printing process, when we check the printing effect of ink,we put the decorative paper under Standard Viewing Environment to do color matching to make sure its stable performance of every lots.