Gloss - A Perception of Surfaces Part 2

Unlike other physical measurements, gloss measurement is not as straightforward. But it isn't difficult either, once one understood how gloss is perceived and interpreted by the human eye.

Gloss is an aspect of visual perception of objects, and it is an attribute of surfaces. With this in mind, any material could be made to meet the requirement of any gloss level as long as the technology exists and the method economic. 

What in this picture makes you think that the car's exterior is "glossy"? What causes this term to come to mind? (image taken from Ziebart)

Gloss - A Perception of Surfaces Part 1

You take a look at the shiny metallic surface of a sleek sports car and you immediately thought of it as "glossy". You saw another car with a body which reflects none of the ambient lighting, absorbing everything like a black hole, and you think of it as "matte".

The glossy surface of an Audi TT (image taken from DeviantArt).

As easy as the word comes to your mind, how does one define "glossy"? This would be important to an engineer, since there has to be some way to control the quality of a surface, and control will not be possible without measurement, and no measurement without a solid definition.

Analog vs Digital

One might have easily heard this hundreds of times - "We are now entering the realm of the digital age" or something along that line. What does that mean, and how much did "digital" influence our life?

To put it simply, a digital system presents data by using discrete or discontinuous values. In other words, there are only yes and no, 0 and 1. Or it may be 1, 2, 3, 4 and so on, but nothing is envisioned or accepted between the numbers, so there is no such thing as 1.4 in a discrete system. If the system is 1.1, 1.2, 1.3, 1.4 and so on, then 1.27 is not accepted within the system as well. You get the picture.

On the other hand, its counterpart, an analog system, uses continuous values for data presentation. Within this system, the data could be divided down infinitesimally. Not satisfied by the data value of 1.2, feeling that it is not accurate enough? Drill deeper and you may get 1.26. Deeper more and you may get 1.257. And so forth the value goes.

Resin Identification Code

If you were to flip over most everyday items made of polymer, especially those which are disposable, you would have noticed the triangular sign with a number within and maybe some alphabets below. This is the Resin Identification Code, and unless you were working with a disposable consumer item and your company is committed to label their product accordingly, you may not have given it  a second's thought.

Image taken from Flickr (by holeymoon)

In order to address the recyclers' rising need for a clear indication of polymer used, Society of Plastics Industry, Inc (SPI) developed and introduced the identification code in 1988. This code is usually found in packaging and containers since these are the main targets of municipal recycling programs, seeing that they are one of common items encountered within residential waste.

The code is used solely to identify the plastic resin in a manufactured item. In fact, the triangular label with 3 twisting arrows along with the number within are commonly misinterpreted. The number within is an arbitrarily chosen number to represent the target plastics, and has nothing to do with ease of recycling. A higher number does not mean that the plastics is harder to recycle.