Why do white clothes get whiter the more they are washed with blue ink?

It has something to do with the color. After blue ink is diluted with water, the washed clothes, especially white clothes, will have a cooler color. Human vision will think that the colder white is whiter. From an optical point of view, colors with high color temperature It will be colder and slightly overcast at noon. The color temperature is about 8000K. At this time, the sunlight is white instead of bright yellow. In fact, white clothes are dyed with a light blue, so that it will match human vision (including daylight film) For the feeling of white, remember that a few drops in a basin of water is enough. If you add more, it will not be white. In the same way, if you wash yellow clothes, you can add some red ink. Will it make it more yellow? If I have a chance, I will do it myself. Try it, haha!!!! You can adjust the color temperature switch of the monitor and try to see if the high color temperature and bluish color are whiter>>>

Additional color temperature knowledge:

About color photography , color temperature affects the feel of a photo. Photos taken in the morning or dusk will appear reddish, and photos taken under tungsten light will appear yellowish. These phenomena are caused by the color temperature at that time not meeting the color temperature standard of the film, resulting in a color cast. In physics, when an object called a perfect black body is completely heated, the temperature rises and it begins to turn red, a red-hot state. If it continues to be heated, it will turn white, a white-hot state. In the red-hot state, the light source emits low energy, and the light wavelength has more red components. In the white-hot state, the light source emits high energy, the wavelength is short, and it has more blue components. The higher the temperature of a luminous object, the whiter the color of the light. The lower the temperature, the redder the color of the light. Under the same tungsten lamp, the light when the voltage is low is redder than when the voltage is high.

Applied to photography, color temperature is the color component contained in the light emitted by a luminous object at various temperatures from red to white. The degree of color temperature is expressed in K, which is +297 degrees Celsius. When the color temperature K changes, the blue light component does not change with the same amount, so the conversion is not very convenient when adding a filter to adjust the color temperature. So there is the design of DM value. The calculation method of DM value is to reciprocate the color temperature K one hundred thousand times. Therefore, the higher the color temperature, the lower the DM value. The lower the color temperature, the higher the DM value. The advantage of using the DM value is that when the DM value changes, the blue component of the light changes by the same amount. In this way, the difference between the DM value of the film color temperature and the DM value of the light color temperature can be used to determine what color temperature filter to use. light microscope.

For example, the color temperature standard of daylight color film is 19DM (equivalent to 5400K). When used in the light color temperature 14DM (equivalent to 7000K), the difference between the two is 5DM. A red R5 filter should be used to reduce the color temperature.

Time light source color temperature K number light source color temperature DM

At sunrise 2000 50

20min after sunrise or before sunset 2100 48

30min after sunrise or before sunset 2400 42

40min after sunrise or before sunset 2900 35

1hr after sunrise or before sunset 3500 29

Sunrise 2hr after or before sunset 4500 22

3hr after sunrise or before sunset 5400 19

Average noon daylight 5400 19

Cloudy 6500-8000 15-13

Fluorescent lamp 7000 14

Electronic flash 5500 18

Blue flash bulb 5400 19

White flash bulb 3800 26

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Photography floodlight 3400 29

Household 500W light bulb 3000 33

Photography tungsten lamp 3200 31

Household 100W light bulb 2900 35