What techniques or tools are used to create this kind of line art?

Question

I like this style of line art:

It looks fairly straightforward to make in Illustrator, but I notice that the lines have a subtle imperfection that makes it look more natural. They aren't uniform in width (especially visible in the trees), and there's some texture to them.

Is this a brush or is it some kind of effect applied afterwards?

Answer 1

It's difficult to tell how this was actually created. It could for example be a scan of a print made with a rubber stamp or even a linocut. It has what I'd call a hand made print look to it.

Anyway, here's one method using Illustrator to create something similar for the trees, as an example.

1. Create your drawing from some thick manual strokes using the Pen Tool, set rounded corners and caps in the Strokes panel. Don't make it too perfect, slight variations will aid that hand-made look later.

2. Select the tree branches and apply Width Profile 1

3. Select all and Expand Appearance, then Expand again to turn everything into outlines.

4. In the Path Finder, hit Union

5. Simplify the path, and use the Rounded Corner Widgets to round all the corners

6. Find a raster image of a rolled ink texture, or perhaps a blackboard (chalkboard) texture, and use the path as a clipping mask on the texture image.

Answer 2

This seems easy to achieve with raster graphics. Let's start with the following image:

Regarding the "not uniform in width" part, lines are wider where they are closer to other dark things. To achieve this:

• Gaussian blur
• Boost contrast to the max

Regarding the "texture" part, the dark areas are darker near their edges. To achieve this:

• (Reduce contrast)
• Enhance edges (sharpen)
• (Add noise)
• (Increase brightness and contrast)

without noise:

with noise:

Sorry, my sharpen filter has too small a radius. You can play around with settings of all said filters.

Then you can convert it to vector graphics.

When working directly with vector graphics instead, the first step would be to "smoothen" the contours, see for example https://gis.stackexchange.com/questions/24827/smoothing-polygons-in-contour-map

Also note:

• The aforementioned filters can be part of physical image acquisition or default scanner software
• From a scientific point of view, the aforementioned filters can be analyzed from the point of view of differential equations, and that can yield information about how the level sets evolve, i.e. how to smoothen the contours to achieve the same (up to numerical imprecisions) result.