Method for characterizing the appearance of a particular object, for predicting the appearance of an object, and for manufacturing an object having a predetermined appearance which has optionally been determined on the basis of a reference object

A method for matching an appearance of an object with a reference object;

• the method comprising the steps of:
• (a) measuring or otherwise selecting reflectance values Rmref(w,h,i) of the reference object using at least one light of frequency (w) and a plurality of predetermined viewing angles (h) and illumination angles (i);
• (b) measuring reflectance values Rmtest(w,h,i) of a test object manufactured by a pre-selected method from a pre-selected material having a pre-selected amount and type of colorant(s) and/or other additive(s);
• (c) calculating values for a surface contribution to appearance k1(w,h,i) of the test object from reflectance values Rmtest(w,h,i);
• (d) making a sample object with predicted reflectance values Rp(w,h,i) by selecting a surface texture similar to that of the test object and characterized by k1(w,h,i) values and a composition such that Rp(w,h,i) values that are predicted to be similar to Rref(w,h,i) values;
• (e) comparing the reflectance values measured on the sample object from step (d) with those the reference object;
• and
• (f) repeating, as desired, steps (b), (c), (d), and (e) changing the surface texture the amount or type of colorants, other additives or manufacturing process until the appearance match between the first and second object is acceptable.