①Technical Overview | Product Specifications
This is a printing technology that emits light under black light, using pigments that glow in the three primary colors (RGB) of red, blue, and green, which emit light under ultraviolet light, and special inks that emit strong light when excited by near ultraviolet light (360-400 nm).
UV emitting ink is an ink that emits light when irradiated with UV light. When UV light is applied to the printed surface, the colorless ink emits color, and when the UV light is cut off, the ink instantly returns to the non-emitting state.
Ink developed by our company
BLACKLIGHT PRINT is a simultaneous printing technology using normal CMYK ink and UV light emitting RGB ink by the special RIP "Simultaneous output function with different inks" developed by SO-KEN using the above UV light emitting ink.
RIP for simultaneous output with different inks
Ability to optimize RGB inks, which are additive color mixing.
Normal ink
CMYK output｜CMY output
CMYK output｜CMY output
luminous ink
CMYK output｜CMY output
CMYK output｜CMY output
As shown in the normal ink diagram, image A is output using subtractive color mixing (CMYK) and reproduces beautiful colors, but if we output image B using the same additive color mixing (RGB) setting, image B will be output in a completely different color than the original image. The software we use has a function to optimize the difference between additive and subtractive color mixing.
Ink specifications and weather resistance
The original ink we developed is compatible with UV wavelengths of 365nm-375nm.
The above images are set to print at different peak wavelengths (from top left, peak wave 365nm/370nm/375nm/380nm).These photos were taken by irradiating the image with a black light peak wave of 370 nm. (Left) It can be seen that if the peak wavelength of the irradiation and the wavelength setting of the printing are the same, the color will be accurate, while if the wavelength of the irradiation and the wavelength setting of the printing are different, the color of the printed material will look different.
About the weather resistance of BLACKLIGHT PRINT
Weatherability is greatly affected by the media used, the lighting (wattage and distance), and the environment (sunlight). In addition, fading is caused by exposure to UV light (ultraviolet rays). Therefore, if the product is not exposed to UV light (ultraviolet rays), the color will not fade. The color will not fade if it is not exposed to UV light, such as in a dark place without sunlight or on a page of a magazine that is usually closed.
| Distance to light source | 10cm~under 30cm |
| Basic fading days | About 15 days |
| If the distance between the printing paper and the UV light source is less than 30cm, the color will fade extremely fast. Check if the distance between the light source and the print media is less than 30cm. | |
| Distance to light source | 30cm~under 80cm |
| Basic fading days | About 90 to 180 days |
| If the distance between the printing paper and the UV light source is more than 30cm, the color will fade at a slower rate. The weather resistance is calculated based on this distance. | |
| Distance to light source | Over 80cm |
| Basic fading days | About 180 to 365 days |
| If the distance between the printing paper and the UV light source is more than 80cm, the weather resistance will be dramatically improved. This is the basic distance for wallpaper. | |
| Sheets of paper | high-quality glossy white paper |
| Lighting | 375nm 40 Type Straight Tube LED Black Light Fluorescent Lamp |
| UV radiation intensity | 66μW/cm² Value at 100cm from the main body |
| luminescence spectrum | 375nm |
| Irradiation time per day | 8 hours |
| The weather resistance is specified based on "appropriate distance and appropriate wattage". Evaluated values for BLACKLIGHT PRINT since October 2010. |
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| How does the color fade? | |
| There is a difference in the fading process depending on the RGB color, with the first color to fade being red, followed by blue, and then green. Since each color fades at a different rate, the number of fading days is determined by the point at which the color balance is lost and the product becomes unusable. Therefore, depending on the color, the number of days may be longer than indicated. Weatherability varies greatly depending on the output of the UV light source, even at the same distance. If you do not use the appropriate wattage, the color may fade extremely quickly. | |
②Notes on installation and use
About the right distance and wattage
Relationship with the wattage of the light source used
Weatherability varies greatly depending on the output of the UV light source, even at the same distance. If you do not use the appropriate wattage, the color may fade extremely quickly.
The proper distance is about the point where the black light print does not feel dark. If the distance is too close, the light will be too bright and weather resistance will be reduced.
| Bright space (with light) | Dimly lit space (low light) | Dark space (no light) |
| More UVs are needed, so the distance will be closer. | Since less UV light is needed, there is more room between the light and the printed material. | Since less UV light is required, more space can be saved between the light and the printed material. |
If the surrounding environment is bright, the distance will be shorter and the wattage will be higher. If the surrounding environment is bright, the distance will be shorter and the wattage will be higher. Therefore, the appropriate distance and wattage will increase, and the color will fade faster. On the other hand, if the surrounding environment is dark, the appropriate distance will be longer and the wattage required will be lower. Thus, the speed of fading is drastically reduced and the weather resistance is improved.
Notes on construction and lighting installation
③About Triggers
Types of triggers to change the design of BLACKLIGHT PRINT
| Triggers for changing designs |
| Irradiate with UV handy light |
| Triggers for changing designs |
| Turn the black light (illumination) on and off. |
| Trigger (1) |
| Turn on the black light illumination. |
| Trigger (2) |
| Just shine the handheld UV light. |
