I love tapered lines in Inkscape because you can make them as simple as you want, or as complicated as you need them. This quick tip will go over the basics of tapered lines, using the Path Effect Editor, and a neat drawing comprised of tapered lines entirely.
1. How to Do Tapered Lines
Okay, so maybe you've never done tapered lines in Inkscape before - let's go over the easiest way first. Select a line tool such as the Pencil tool and head to the menu where you see Shape. Change this to Ellipse.
Give it a test and draw a little line. Wow, that was easy.
A few issues I'd like to point out though.
Since this type of tapering is actually using an ellipse stretched out over a path, this tapered line is essentially just an object being manipulated as a path. This means that the Fill with fill the inside of your line and that the Stroke will put another line outside of your line. Bummer.
Also (for the same reason) no matter how you re-size or redraw your tapered lines, the thickness of your line will always be the same because it's referring to that same ellipse shape every time.
2. Path Effect Editor
Head up to Path > Path Effect Editor to open up one of the coolest path editors ever. To remedy our previous line thickness issue, select your path and click on the Pattern Along Path under Effect list. This will bring up all of your options to edit your tapered line. Easily enough, you can just go to Width and adjust it to your liking.
3. Using Your Own Shapes
The ellipse works well, but I've found a solution for tapered lines that I much more prefer (most of the time). To start out, use the Rectangle tool to draw a perfect square. Then, rotate it 45 degrees. With it still selected, head up to Path > Object to Path.
Next, shrink it down nice and flat. Then grab the Nodes tool and select the two middle nodes so that we can Make selected nodes symmetric (which rounds them also). This is our new tapered shape that we'll be using.
The easiest way to use this shape as our taper is to select it, copy it to your clipboard, and select Shape: From clipboard on either the Pencil tool or the Pen tool.
In order for me to compare my new tapered line with the ellipse line, I had to use a pretty neat feature. If your custom tapered shape is still copied to your clipboard, you can select any existing line, go to the Path Effect Editor, and click "Paste" by the Pattern source.
Now that I have two of the exact same paths with different shapes, we can compare. The top one is using my custom shape while the bottom one is the ellipse. Look at the end of the curl - the custom shape has such a sharp, gradual finish (which I love). The ellipse path is just a tad stubby on the ends. I know, this is pretty picky, but at least I got to show you how to use custom shapes, right?
4. How About a Drawing?
Let's draw a rough human eye! They always require such nice curves and tapered ends, so I thought this would make a great example on using tapered lines. I'll be using my custom tapered shape, but you can of course use the Ellipse. With the Pencil tool, make sure you have Smoothing to at least 50. Then, just do a clean sweep of the brush across the canvas. After a couple of tries, you'll get a line that looks perfect. Continue doing this until you have an arrangement similar to the one below.
Make sure you keep that Path Effect Editor opened to adjust the Width of these lines.
Now let's do some eyelashes. Keep that Pencil tool selected and change the Shape to Triangle in. As you can see below, you get a semi-tapered lines which will be great for some eyelashes.
For the most natural looking eyelashes, I found that just free handing these strokes looked best. This will probably take a few times, but just keep a graceful hand and go with the flow. Don't forget that you can adjust the width of these in the Path Effect Editor also! (I certainly had to.)
Eventually, you'll end up with something like this for the framework of an eye.
That Finishes Things Up!
We went over the simplicity of using ellipse tapered lines and even using our own custom drawn shapes as a path effect. Try some different shapes and play around with the settings in the Path Effect Editor to come up with some neat tapered line designs. Thanks for reading!