QIP Gloss Meter

Application of the Gloss meter

The importance of measuring gloss is realized very quickly when the appearance of a production job is suddenly different than expected or does not match a previous run. What can you do at this point? Quickly explain to your customer that the look of the newly printed piece is far superior to the previous run or their expectations? Start blaming the gloss suppliers, pressmen, press, coater, press speed, paper or stock? No, you simply explain to your customer that you are going to get a gloss meter so this will not happen again.

These devices are indispensable quality control tools that work similarly to a densitometer. A gloss meter is simply placed over the area in question and activated by pressing a small button to engage the lamp. This functionality is exactly the same as that of a densitometer. This, technically speaking, is where the similarity ends. A densitometer is designed to eliminate the gloss in its interpretation of ink density. It accomplishes this by nature of its optical geometry. The standard optical geometry of a graphic arts densitometer is 45°. If you view something at a 45° angle the gloss influence is minimized or, in some cases, eliminated. Therefore, to read gloss, new standards for optical geometry help maximize the gloss influence so a gloss meter can interpret a gloss value and determine if a sample is deviating from a norm with respect to its gloss.

A printer in the commercial printing or packaging market must read gloss because it has a profound impact on the appearance of a printed product. Your colors can be perfect. Ink densities can be exact. The stock and ink can be the same from run to run. However, if the gloss level is inconsistent the appearance will be drastically effected.

Also, how many times has a customer or salesman brought in a sample of a previously run job for you to bid? You may be asked to simply match the gloss appearance of a similar job or match the exact job that was run elsewhere. How do you handle this? Standard viewing conditions in a viewing booth are designed to match color, not determine gloss level. In a viewing booth the angle of view is supposed to be consistent, but due to the fact that people are of different heights this angle of view is always different. Every angle at which you view the sample will produce different effects. There is a better way. Use a gloss meter to monitor the gloss level so you can communicate an exact gloss value number to your suppliers, pressmen, and customers.

The industrialized nations of the world have decided to standardize the measurement of gloss. Gloss meters that comply with these standards are readily available to everyone in the industry. The most popular optical geometry is 60°. The QIP GlossMate 60° is ideal for the graphic arts. This optical geometry provides the user with a broad range of gloss level measurement possibilities. Graphic art coating applications, from dull to bright, fall within the parameters of a QIP GlossMate 60°. This has been the instrument of choice for most printers.

However, if your customer requests varying gloss levels from time to time it is best to use an instrument with a three angle optical geometry. The best optical geometry for very high gloss (above a number 90) is 25° while the best optical geometry for very low gloss (below a number 40) is 85°. The QIP GlossMaster 25° 60° 85° has all three optical geometries built in. This is the answer to your most exacting gloss measurement applications. All QIP gloss meters can be attached to a computer for downloading data into any SPC system.

Gloss is measured in all industries where color and appearance are critical. The paint, plastics, ceramics, paper, textiles, and coating industries all use gloss meters each and every day. Varying optical geometries that are optimized for each industrial segment allow for exact gloss value measurement.

Printers today are investing in gloss meters to provide their customers with the most consistent printed products possible. The use of a gloss meter will minimize customer quality complaints with respect to appearance, minimize make readies, improve productivity, make reruns a snap, and provide the opportunity to improve profits through better communication. A gloss meter investment will be justified the very first time you use it.

Measuring Gloss in Theory and Practice Part I

What is Gloss? In everyday language we use the term "gloss" to express the capacity of surfaces to reflect light in some directions than others. Due to this phenomenon the brightness of a surface is increased or reduced with changes in the observer's angle of vision.
If a printed surface is illuminated in a directed way, the following types of reflection can be differentiated:
Specular reflection at the surface of glossy objects.
and diffuse light scattering at the surface of semi-matte and matte objects determine the perceived glossiness.
Light scattering resulting from pigment particles is responsible for the perceived color.

Why is it Necessary to Measure It? W
Everyone has an idea of what the terms "glossy" and "matte" mean. In case of terms like "satin-gloss", "high-gloss" or "satin-matte", however, which are often used in the printing industry, different observers may reach different conclusions.

For many applications, however, it is important to determine a specific gloss.

The perceived gloss is subject to 4 factors:

1. Surface condition Physics, reflection
2. Source of Illumination Physics
3. Eye Physiology
4. Observer Psychology

Consequently, direct gloss measurement is impossible. Therefore the reflecting properties of the surface are measured which contribute to the perceived glossiness.
Thus, not the gloss of a surface is measured but the reflectometer value R', which can be used as a measure of the reflecting properties of a specimen.

Delivery Specifications
In order to facilitate communication between supplier and customer, it is necessary to speak the same language if a certain degree of gloss has to be defined for a product.

 Revised February, 2006

 GWJ Co.
Hacienda Heights CA 91745-4148

Phone: 626-336-1134  800-336-1138 (USA)
Fax: 626-336-2409

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