Aligning Spectral Reflectance and Fastness Metrics across Printing Technologies
Aligning print technologies requires specifying CIEDE2000 tolerances below 0.8, capping metamerism indices under secondary illuminants, and adjusting wet crock floors.
Spectrophotometer Geometry
Optical Configuration
Spatial relationship between the light source and the sensor defines how a color measurement device captures data from a sample. Spectrophotometer geometry determines whether the instrument accounts for surface texture and gloss when reading a fabric.
Measurement Mode
Diffuse d/8 geometries use an integrating sphere to provide a uniform field of light that minimizes the influence of the weave pattern. This spectrophotometer geometry is the standard for most textile applications because it provides consistent results on soft, matte surfaces. Some instruments allow for the exclusion of the specular component to better match the human eye’s perception of color.
Texture Impact
Directional 45/0 geometries are more sensitive to the orientation of the yarns and the shadows cast by the fabric structure. Using this spectrophotometer geometry on a ribbed or velvet fabric will result in high variability if the sample is rotated. Most apparel buyers specify the required instrument setup in their color manuals to ensure that data from the mill matches data from the brand office.
Data Compatibility
Color values measured on different instruments can only be compared if they share the same setup. Standardizing the spectrophotometer geometry across the supply chain is a basic requirement for digital color approval.