Paper brightness and whiteness may seem synonymous but are different concepts that only good paper manufacturers can tell.
We use paper every day. Sometimes as an A4 sheet for printing or a diary page to make notes, even as our school notebook, and so on. While using, we come across the pages with different whiteness and brightness levels which we often interchangeably refer to. However, these terms are not the same. While paper brightness refers to the ability of the paper to reflect light, whiteness refers to the color or the shade of the paper. In the following article, we will throw light on the differences between the two. So read on.
Paper Brightness
As mentioned above, paper brightness concerns the blue light reflectance that ranges between zero and a hundred percent. The higher the number, the brighter the paper is. This light reflection is measured differently, i.e. on a different wavelength than that of whiteness. Paper manufacturers make use of a paper brightness tester to test this brightness. They use three standards to measure paper brightness:
- TAPPI/G.E Brightness
- ISO Brightness
- D65 Brightness
Paper Whiteness
When a human eye looks at a sheet of paper, it notices a red, blue, and green reflection. This reflectance is called paper whiteness. When this reflectance consists of more reds the whiteness appears warm. On the other hand, if there are more blues, it appears cool. Moreover, the environment (outdoor or indoor) in which one views the paper also affects the whiteness.
Optical brightening agents are used to boost the whiteness of the paper. In the outdoor light, this sheet will appear whiter than indoors. In contrast, a sheet with a low brightening agent will appear whiter indoors and dull outdoors.
Bottom Line
Both paper brightness and whiteness are significant factors that must be considered while selecting an ideal paper. Connect with a reliable testing machine manufacturer to source for paper brightness, compression, folding endurance, absorbency, plybond tester, and other equipment.
