How Do You Check The White Ink Layer Quality On Transparent Film?
The quality of color graphics printed on clear film is highly dependent upon the white ink background. The white background enhances the chroma of colors, improves the readability of bar codes or QR codes and helps meet target color specifications. Color ink quality specifications are widely understood and measured with industry-standardized instruments and techniques. White ink specifications require different instruments and techniques in order to obtain accurate and actionable measurements.
The quality of the white ink layer can be measured by two criteria:
- The opacity or hiding-power of the white ink layer
- The homogeneity or smoothness of the white ink layer
Today a standard densitometer is used to measure the opacity of the white ink. The density of a black reference is compared to the density of the white sample. Because density is a logarithmic value the measurement resolution is quite low on bright samples while it is quite high on dark samples. It is not possible to detect small variations on the white ink layer.
The Beta OPA-DENS, an easy to use, application-specific measurement device that measures the small variations on bright samples with high resolution.