Transparent and translucent plastics require a method based on the optical question. A clear film may need transmitted color and haze; a translucent housing may need its appearance over a defined backing. One result cannot substitute for the other.
Choose the measurement mode
| Requirement | Method |
|---|---|
| Color of light passing through | Transmission color with fixed specimen position and path length. |
| Appearance of a translucent part in use | Backed reflectance using the specified backing and thickness. |
| Cloudiness or scattering | Haze and luminous transmittance under the nominated method. |
Control thickness and surfaces
Transmission color changes with optical path length, so compare specimens of the same thickness or report thickness with the result. Keep surfaces clean and unscratched, avoid fingerprints, and define whether coated or textured faces point toward the source. Flat, parallel specimens are easier to present repeatably than curved parts.
Do not confuse color, transmittance and haze
Two plastics may have similar transmitted Lab values but different total light transmission or haze. ASTM D1003 addresses haze and luminous transmittance of transparent plastics; color measurement should be specified alongside it when both properties matter. Highly diffusing samples may require a different method.
Build the production method
- Choose transmission or backed reflectance from the product requirement.
- Define thickness, aperture, specimen position and orientation.
- Set the illuminant, observer, color space and difference formula.
- Measure enough positions to represent film or sheet uniformity.
- Track haze or yellowness separately when they are release criteria.
The SD-800B and SD-900B are the relevant products for transmission and haze workflows. See also reflectance vs transmittance, haze and the complete plastics guide.
Last reviewed 21/09/2026 · Level: Intermediate
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