This is how you work with Line Segments using the Width Tool in Adobe Illustrator.
So, we're going to go to our Tool Panel. We're going to select the Pencil. We're going to click 1 point, and let's click another point. And, that's all we've got to do.
We're going to de-select it by clicking our Selection Tool and clicking away or we can click the Pen Tool or the letter "P" and you can get rid of that.
Now that we have this on the board, we'll notice that this is actually a stroke, a line, whatever you want to refer to as, but you'll notice that it has a certain thickness to it.
And you want to change that thickness and one way you can change that thickness is to go to your Stroke Panel, which is in your Windows Panel on the right. It should be there by the fold, if not you can go to your Window Menu item, go down to Stroke, select that, and it will come up on the side.
And with it selected, you can change the weight of the stroke by clicking down, clicking up, and you'll notice that it increases and decreases. Now, that's one way to actually change the width of the actual line segment.
Another way is to select the Width Tool, which you'll note is on the actual Tool Bar. It's a funny-looking shape.
You click this, and once you click that tool, if you hover over your line segment you'll notice that a little circle appears.
And at any point you can click that circle, drag it up or drag it down. You 'll notice that it's flexing as we move it. If we drag it farther up, and down, you'll notice that we can increase or decrease the size.
Now, we're not limited to just doing it at 1 point, but we can edit that point by grabbing the little circle that's on the outside, or we can grab another point, change that, and you'll notice that it flexes according to the width points that you already made.
So we can make them extremely small, ridiculously large, or just normal.
And that's how you work with the Width Tool in Adobe Illustrator.