Brightness of Paper

When deciding between white or coloured paper for your next printing project, you may think your decisions are over when you have settled on white. However, just as there are a myriad of colours in the rainbow, so too are there a myriad of whites and different brightnesses to choose from too.

Brightness of paper is also known as ‘diffuse blue reflectance factor’ and is measured at an effective wavelength of 457 nanometres (nm). Brightness is just one measure of the colour of white and off white paper and is measured by the reflectance of light off of the paper from a specific wavelength at the blue end of the colour spectrum.

The brightness measure is effected by yellowness in the paper and as a result paper of his this shade is not considered white, or even off white. Whereas paper with a slightly blue colour is more pleasing to the eye and is considered to be whiter. Cellulose pulp naturally has a creamy complexion and even when it is bleached, its yellowness is still apparent. So, to make paper made from cellulose pulp more appealing to the eye and appear whiter, a trace of blue or violet is added when it is being made and the final result appears whiter.

When alerting paper in this way however, the extra dye which has been used to achieve whiteness has increased the proportion of light absorbed by the paper. As a result, the paper appears duller than it was before it was altered by the dye.

Therefore, when you are looking for the brightest and the whitest paper, make sure you realise these two qualities do not go hand in hand. Often one will be sacrificed to achieve the other, depending on the source of the pulp used to make the paper.

For more information about how you paper arrived at its white and/or bright stage, contact Print Compare now.