Value Guide

To help students learn to improve their shading skills, start with the slideshow where students can see the importance of using a wide range of values.  Next, we provide a "value guide" so they can evaluate numerically any value they want to duplicate.  Values 0-7 can be achieved with an HB pencil, but 8-10 require a softer pencil such as a 6B pencil like these.  The practice page and portrait page allow students to practice their shading skills.
Picture
This slide show is a good starting point.  Students can see that the artists started much like anyone else but a few years of practice made a huge difference.  Students may notice better proportions, an imprioved use of space and other elements of visual art but most dramatic is the improved use of value.  
View slideshow

Value guide 

This is the guide.  Students shade with an HB pencil to try to match the values 0-6 while 8 and 10 require a softer pencil such as 6B pencil like these. 

Practice

This is a practice sheet where students shade cylinders and spheres to practice identifying and matching values

Portraits

This is another practice sheet where students are given portraits that are cut in half and they have to match the missing values in the second half.  (might chose one instead of both) Extension: students do this with a portrait of their choice.