I use this worksheet to give my drawing students some practice with making value scales. ("Value scale" might also go by the name "luminosity scale," or "tone scale.")
This worksheet asks them to use three different types of shading to complete the value scales: Blended Shading, parallel hatching, and stippling. I have a PowerPoint presentation on value and shading that I will post here soon.
There's examples of each type of shading on the worksheet. The art on the worksheet was created by me or is being reused according to the terms set by its creators. Art credits are in the lower left corner of the page.
The download includes an example of a completed worksheet.