Meaning
Colorimetric measurements of paperboard products determine how bright and neutral a material appears to the human eye under standard light sources. The cie whiteness index evaluates these properties by combining reflectance data across the visible spectrum. This value helps manufacturers assess the visual quality of raw packaging materials.
Formula Application
Mathematical models calculate how raw substrate colors shift under different lighting conditions. The formula for cie whiteness uses specific weighting factors for the green and blue regions of the spectrum. This calculation yields a single number where higher values represent a more neutral white, which is essential for premium print reproduction.
Supply Standard
Supply agreements for printed cartons specify minimum optical properties to ensure brand consistency across retail shelves. A contractually mandated level of cie whiteness binds the board manufacturer to deliver materials within a narrow optical range. If the delivered board falls below the minimum threshold, the buyer has the right to refuse the batch or demand price concessions.
This standard prevents dull or yellowing boards from entering the printing line and ruining the graphic layout.
Defect Allocation
Quality disputes between printers and board suppliers often hinge on baseline optical performance. When a batch exhibits low cie whiteness, the printer cannot achieve the correct color balance without adjusting ink density. These adjustments increase production costs and slow down the runs.
The supplier must cover these losses if the board fails to meet the specified contract tolerances.
