Correlation between gloss reflectance and surface texture in photographic paper

Area of Science:

• Materials Science
• Surface Metrology
• Imaging Science

Background:

• Photographic paper gloss is influenced by surface texture.
• Quantifying this relationship requires advanced surface analysis techniques.

Purpose of the Study:

• To measure and characterize the surface textures of diverse photographic papers.
• To correlate surface texture parameters with gloss measurements.
• To evaluate the impact of different objective lenses on measurement accuracy and correlation strength.

Main Methods:

• Laser scanning confocal microscopy (LSCM) was used to measure surface textures.
• Four objective lenses (5×, 10×, 20×, 50×) were employed for measurements.
• Area-scale fractal dimension (Das) and area-scale fractal complexity (Asfc) were calculated.
• Texture parameters were compared with gloss measurements.

Main Results:

• Area-scale fractal dimension (Das) and complexity (Asfc) showed the strongest correlations with gloss.
• Lower magnification objectives (5× and 10×) produced stronger correlations (R² > 0.8) than higher magnifications (20× and 50×, R² < 0.5).
• Spiky measurement artifacts, prevalent at lower magnifications, appeared to enhance the correlation by amplifying surface features.

Conclusions:

• Fractal analysis, particularly Das and Asfc, is effective for characterizing photographic paper gloss.
• Lower magnification LSCM measurements, despite artifacts, can provide robust gloss-texture correlations.
• Artifacts in surface texture measurements may unexpectedly improve gloss correlation analysis.