For your print information: Opacity and brightness

There is more to paper than meets the average eye. For something that is so common, it can have a great affect on how colour is perceived on printed products. Paper has many forms and attributes and can influence how consumers respond to your printing services. It could be considered your modern canvas for print.

Properties of Paper: Opacity and Brightness

Opacity defines the level of reflection and absorption of light as it passes from air to fibre through the paper. Brightness describes how brilliant a sheet of paper appears. This is not interchangeable with the whiteness property of paper as it only measures the appearance of colour at the blue wavelength rather than all wavelengths. This wavelength is measured since the human eye is more receptive to blue-whiteness. It appears brighter and psychologically, we associate blue-white things as new as opposed to yellow-white objects, which appear old. These factors should be considered when choosing an appropriate stock for products.

Impact of Opacity & Brightness

Opacity

By understanding the characteristics of paper and its composition, you can be more conscious of the several factors that influence a paper’s opacity. Some attributes of paper such as fillers, dyes, brighteners, colour composition and types of fibres can change the show through on the reverse side. Also take into consideration the coating of the substrate, which affects the internal light scatter properties, and thus influences the opacity of a paper.

A high opacity paper is appropriate for double-sided printing, especially with heavy coverage. This will avoid strike through, which is the visibility of excessive ink penetration through paper. Therefore, selecting a high opacity paper prevents obstructing the readability of the content. In the end, it’s beneficial to invest in paper with a higher level of opacity in order for your paper to have a higher visual quality.

Brightness

As light reflects off the paper, transparent inks absorb some of the light, thereby subtracting certain wavelengths while reflecting others. This produces the perception of colour. The brightness of the substrate affects how those wavelengths are reflected. Therefore, brightness influences the purity of colour that we perceive. Essentially, brightness is referring to the print contrast of the paper, which affects the image quality. In fact, maximum print contrast is best achieved using a paper with a blue tint that has good opacity. However, because very bright papers emphasize the blue visible spectrum, this may distort some colours. This can be problematic when colour accuracy is crucial. However, generally speaking, bright papers are great for advertising and commercial purposes so that the content will command the reader’s attention. Highlights, midtones and shadows will be more prominent. On the other hand, paper used for books, like novels, would likely use a lower brightness to prevent eye-strain on the reader for long duration.

In essence, the choice of level of brightness as well as the opacity is dependent on the end use application. When buyers purchase print, they are looking for a printer that will produce a desired level of quality. In turn, the printer relies on the consumables and raw materials involved in the process to produce that quality product. Now that you understand brightness and opacity, you can add it to the list of variables you consider when planning out the best graphic arts solution.