These scales were designed as a two-piece set, primarily for footwear and tire track impression photography. They provides accurate reference measurements when placed evenly in the same plane in two-dimensional or three-dimensional impressions. Excellent for verifying perspective distortion. These rigid plastic scales have a flat, non-reflective finish to eliminate reflections during photography. The L-shaped scale measures 30cm x 15cm and includes a separate 15cm scale. The reversible scales are white with black printing, and the reverse side is black with white printing. Accuracy verified with a NIST traceable standard.