Next, you'll measure the medulla, but because this particular medulla varies so much from thin to thick, you'll need to make several measurements and average them.

Again, being sure you're still on CrimeSceneHair.gif with Line selected, measure across five different widths of the medulla. Be sure to measure both the thickest and the thinnest areas you can find.

Once you've made four measurements and recorded them on your Data Sheet, then add them together, and divide by 4 to find the average.