bluing for whiter whites

How laundry bluing works

Colour experts can distinguish about 300 shades of white. Some shades are a pink-white, some a yellow-white. The white which is the brightest of whites is one with a slight blue hue. Because blue-white is the most intense white, most artists, when painting a snow scene, will use blue to intensify the whiteness.

The proof comes when two pieces of fabric are placed under a spectrograph: the one with blue added will reflect more light, making the fabric appear its whitest.

To test for yourself, place a brand new white T shirt next to one which has been through six months of washes. Notice the difference? Viewed on their own, both will look white. When placed next to each other, the new one will appear much whiter, and a blue hue will be evident.

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