The techniques that are shown in this value chart are hatching, cross hatching, stippling and random marks. They all are different ways in which you can show value. Hatching means you are making straight lines in one direction. Cross hatching means making straight lines in multiply directions. Stippling means making dots. Random marks means you make any random mark you want to shade it in. The more you do of any technique, the darker it gets. The softer the grafite the darker the marks. This can show value because you can see the light and dark and understand the shadowing. This helps when making a 3D shape.