Deinkability Score Impact on EPR Eco Modulation Fees in Recycled Stock
Deinkability scores under INGEDE Method 11 directly determine EPR eco-modulation fee surcharges or discounts on printed recycled paperboard packaging.
CIE L a B Color Shift
Color Measurement
Measurement of the variation in the colour coordinates of paperboard provides a numerical description of how the appearance of a material changes. This change, described as a cie l a b color shift, tracks the movement of coordinates on axes representing lightness, redness, and yellowness.
Degradation Cause
Exposure to ultraviolet light, heat, or humidity during storage and transport can cause chemical reactions in the lignin and optical brighteners of the paperboard. These reactions alter the reflectance spectrum of the substrate, which is recorded as a shift in the values of the colorimetric axes. For example, a positive shift on the b axis indicates that the material is becoming more yellow, which is a common sign of aging in mechanical wood pulp papers.
Color Tolerance
Printed packaging requires a low level of colour variation to ensure that products appear identical when displayed on retail shelves. Brand owners often specify a maximum color difference value that the converter must not exceed during the print run. Spectrophotometers measure the shift across multiple points on the printed sheets to confirm that the variation remains within acceptable limits.
If the shift exceeds the limit, the batch is rejected to protect the brand identity. This measurement is critical for maintaining consistency across different production batches and printing plants.