Color Matching

Human beings can differentiate between about 10 million different colors, but our ability to interpret and describe them varies widely. The same individual can perceive color differently based on factors such as illumination, viewing angle, and even mood.

Cast Stone manufacturing is governed by ASTM 1364 – Standard Specification for Architectural Cast Stone in which reference is made to ASTM D2244- Standard Practice for Calculation of Color tolerances and Color Differences form Instrumentally Measured Color Coordinates.

By using an instrument called a Spectrophotometer as described in the fore mentioned ASTM specifications, color matching is no longer subjective to a myriad of variables. Color matching is a science. The diagrammatic report above shows a color labeled “standard” in the leftmost column. This represents the color selected by the Owners Representative. The next 6 columns are labeled “batch 1 through batch 6”, these represent six different color samples made to submit to the owner for approval. Amongst other factors, a critical piece of data is in the row labeled “dE*” this represents the overall deviation of the sample color from the standard color. Less than 6 is the goal. As you can see all samples scientifically conform to the standard. Thus the choice is now to be based on cost of manufacturing (greater pigment loading increases the project cost) and the aesthetic difference, if any is discernible to the Owner.

Please review the attached white papers for more information on color matching and color in general.