Color is what a person perceives. It is the result of the physical modification of light by an object observed by the human eye and interpreted by the brain. Color of an object comes from the selective absorption and scattering of light.

Appearance is what we see. It is not just the color of an object but all the items that impact the interpretation by the brain. This perception by the brain is affected by the illumination, the viewing conditions, defects in the eye, what surrounds the objects, the possible fluorescence of any of the objects within view, the psychological state of the viewer and the surface quality of the objects.

In plastics, the only aspect which the resin manufacturer can control is the color of the resin. For this reason, we usually attempt to match the color of the glossy side of our molded standard to the color of your target. The final appearance of the plastic part can be impacted primarily by the converter or molder, and depends on the processing parameters and the tooling used.

Any attribute of light source, object and observer, including color, that affects the brain’s interpretation of a scene contributes to appearance.

Gloss and surface texture of plastic parts require special attention in relation to appearance. Since appearance integrates all the parameters, any differences in gloss or texture between target and color match can play a prominent role in the visual and measurement evaluations. These two issues can result in visually acceptable color matches which measurements might show as unacceptable. The reverse is also true. These differences, which may prevent accurate measurement, may not be under the control of the visual color matching team. The acceptable color match must account for these variables.

A second aspect of appearance critically important to any color match is the polymer itself.

Many polymers have significantly different inherent colors and this can create issues. This creates unique and difficult problems for you, SABIC", and your SABIC ColorXpress™ Services Team. For example, Opaque Cycolac* acrylonitrile butadiene styrene (ABS) resin cannot be made to appear identical to transparent Lexan* polycarbonate (PC) resin.

Some of the major factors affecting appearance are:

• Target and color match are different polymers.
• Surface texture and/or gloss for target and color match are different.
• The manufacturing process for target and color match are different.
• Heat stability requirements for target and color match are different.
• Weathering and/or lightfastness needs for target and color match are different.