Phone: (914) 381-2400E-Mail: customerservice@marvalindustries.com
Thick and thin plastic sections can look different even when the processor is using the same master batch. This is especially true in transparent or translucent materials, where appearance depends on light passing through the section as well as light reflected from it. It is not a rule that every thicker section looks darker or that every fully opaque part changes color with thickness. At Marval Industries, we offer opaque and transparent color concentrates, so the intended optical appearance belongs alongside the shade when defining a color target.
The first distinction is the material's optical behavior at the thickness being viewed. The terms transparent, translucent, and opaque describe different relationships with light and the background. They are useful for interpreting a color difference because the background contributes differently in each case.
● Transparent material transmits light with little diffusion or scattering, so it allows you to see through the section. A transparent colored material can still selectively absorb light; transparent does not mean colorless.
● Translucent material passes some light while scattering or absorbing part of it. It does not fully hide what is behind it, so both the material and its backing can affect the appearance.
● Opaque material hides the background at the thickness being assessed. When a section is sufficiently opaque, you cannot assume a transmission-and-background explanation accounts for its color difference.
Different section thicknesses present different path lengths for light passing through the material. Absorption and scattering affect how much light is transmitted and how the material appears, so an unchanged color formulation does not make every thickness optically equivalent. Datacolor identifies film thickness as important when judging transparent and translucent color matches. The key question is how the material behaves at the section being assessed, not whether the concentrate has changed.
HunterLab reports a demonstration using translucent plastic plaques made from the same resin at different thicknesses. In its account, the thinner plaque transmitted more light, while the thicker plaques appeared more opaque. In the reported reflected-light assessment, the thinner plaque produced a darker reading because more light passed through it instead of being included in that measurement. This is a vendor-reported observation under the comparison conditions it describes, not a prediction that every thicker plastic section must look darker.
When a section does not fully hide its background, changing that background changes the optical comparison. HunterLab’s guidance for transparent bottles identifies different backing colors as a source of different appearance and recommends a consistent background for its measurement method. Konica Minolta likewise relates plastic opacity to formulation and sample thickness, with light and dark backgrounds used to assess the degree of hiding. A thin section viewed over one backing is therefore not the same comparison as a thicker section viewed over another.
A flat color sample and the finished part can also present different viewing conditions. HunterLab’s bottle guidance identifies rounded geometry, placement, and wall-thickness variation as measurement factors, rather than treating a whole bottle as identical to a flat specimen. The practical implication is to identify which part of the product represents the color being judged. Comparing unlike shapes without recognizing the section and backing can mix several appearance differences into one judgment.
Konica Minolta’s plastics guidance explains that surface finish and texture can change perceived or measured color independently of background transmission. Moving the comparison to a different light source introduces another condition, so it does not isolate the effect of section thickness. A thickness explanation does not, by itself, explain why streaks or specks appear. Distinguish those patterns from an overall translucency difference before treating them as the same color problem.
Before requesting a color adjustment, identify which thick and thin sections you're comparing and whether you're viewing them over the same backing. Keep an intentional thickness difference visible in the color discussion rather than asking an unidentified flat sample to represent every section. Where the finished design contains both thick and thin areas, judge the intended appearance at the relevant sections before deciding that the concentrate must change.
315 Hoyt Ave Mamaroneck NY 10543
customerservice@marvalindustries.com
customerservice@marvalindustries.com
(914) 381-2400
