Chart for evaluating skin color and its application to efficacy evaluation of anti-aging and skin lightening products

Abstract

The present invention relates to charts, stacks and methods for evaluating skin color of a mammalian subject. The chart may include a substrate and an indicia visible from a first side of the substrate that includes a plurality of images of mammalian skin tones having varying degrees of yellowness, wherein each indicia is correlated with an index value. Also, the present invention relates to packaged topical cosmetic products that include a skin chart as well as to methods for evaluating anti-aging and skin lightening products.

1 . A chart for evaluating skin color of a mammalian subject comprising:
 (i) a substrate; and   (ii) an indicia visible from a first side of the substrate and comprising a plurality of images of mammalian skin tones having varying degrees of yellowness,
 wherein each indicia is correlated with an index value. 
   
     
     
         2 . The chart of  claim 1 , wherein the number of the images of mammalian skin tones visible from the first side of the substrate ranges from 2 to 10. 
     
     
         3 . The chart of  claim 1 , wherein the chart includes 10 images of mammalian skin tones, where a first image corresponds to extremely low yellowness of the skin and a last image corresponds to extremely high yellowness of the skin. 
     
     
         4 . The chart of  claim 1 , wherein the images of mammalian skin tones are replications of facial images from real skin of men and women. 
     
     
         5 . The chart of  claim 1 , wherein the substrate is paper or a cardboard. 
     
     
         6 . A stack of charts for evaluating skin color of a mammalian subject comprising:
 (i) a plurality of charts, wherein each chart represents a different facial color shade ranging from light- to dark-complexioned facial color and comprises:
 (a) a substrate, and 
 (b) an indicia visible from a first side of the substrate and comprising a plurality of images of mammalian skin tones having varying degrees of yellowness, wherein each indicia is correlated with an index value. 
   
     
     
         7 . The stack of  claim 6 , wherein the stack comprises 9-18 charts. 
     
     
         8 . The stack of  claim 6 , wherein the stack comprises 9 charts. 
     
     
         9 . A stack of charts for evaluating skin color of a mammalian subject comprising:
 (i) at least one chart comprising:
 (a) a substrate; and 
 (b) an indicia visible from a first side of the substrate and comprising a plurality of adjacent rows, each row comprising a plurality of images of mammalian skin tones having varying degrees of yellowness, wherein each indicia is correlated with an index value, and wherein each of the adjacent rows represents a different facial color shade ranging from light- to dark-complexioned facial color. 
   
     
     
         10 . The stack of  claim 9 , wherein the chart comprises 9-18 adjacent rows. 
     
     
         11 . The stack of  claim 9 , wherein the chart comprises 9 adjacent rows. 
     
     
         12 . A packaged topical cosmetic product comprising:
 (i) a topical cosmetic composition comprising an effective amount of an anti-aging or a skin lightning agent and a carrier;   (ii) a package for receiving the cosmetic composition; and   (iii) one of:
 (a) a chart for evaluating skin color of a mammalian subject inserted within the package or forming one or more panels of the package, the chart comprising: a substrate; and the indicia visible from a first side of the substrate and comprising a plurality of images of mammalian skin tones having varying degrees of yellowness, wherein the one or more panels of the package present facial color shades ranging from light- to dark-complexioned facial color; or 
 (b) a stack of charts for evaluating skin color of a mammalian subject comprising a plurality of charts, wherein each chart represents a different facial color shade ranging from light- to dark-complexioned facial color and comprises:
 (1) a substrate, and 
 (2) an indicia visible from a first side of the substrate and comprising a plurality of images of mammalian skin tones having varying degrees of yellowness, wherein each indicia is correlated with an index value; or 
 
 (c) a stack of charts for evaluating skin color of a mammalian subject comprising at least one chart comprising:
 (1) a substrate; and 
 (2) an indicia visible from a first side of the substrate and comprising a plurality of adjacent rows, each row comprising a plurality of images of mammalian skin tones having varying degrees of yellowness, wherein each indicia is correlated with an index value, and 
 
  wherein each of the adjacent rows represents a different facial color shade ranging from light- to dark-complexioned facial color. 
   
     
     
         13 . The product of  claim 12 , wherein the number of the images of mammalian skin tones visible from the first side of the substrate ranges from 2 to 10. 
     
     
         14 . A product of  claim 12 , wherein the images of mammalian skin tones are photographic replications of facial images from real skin of men and women. 
     
     
         15 . A method of creating a chart for evaluating skin color of a mammalian subject comprising:
 (i) analyzing a plurality of facial images for their color properties: skin brightness (L*), redness (a*), and yellowness (b*);   (ii) measuring the L*, a* and b* values for each analyzed facial image;   (iii) sorting the measured b* values to show a low-to-high scale;   (iv) normalizing the measured b* values to the +/−4 sigma range to form a distribution of 1-10 point scale;   (v) selecting target values for the L* and a* values;   (vi) selecting facial images that correspond to the distribution of 1-10 point scale, wherein the a* and the L* values are target values for the different b* values at each scale point;   (vii) printing representative facial images corresponding to the distribution of 1-10 point scale onto a substrate.   
     
     
         16 . The method of  claim 15 , wherein the target value for L* is 69 and the target value for a* is 14.8 when choosing various scale points for the b* values. 
     
     
         17 . A method for evaluating of anti-aging and skin lightning products comprising comparing a skin tone of a subject to the chart of  claim 1 .