Grunge Brushes with Inkscape - An Illustration Tutorial

As promised in my previous Inkscape tutorial (Creating a Sunburst Effect) this tutorial will explain how to make your vector images have a beat-up, abused look. Vector graphics are very sleek and have and "feel" very smooth - sometimes this is the desired look, for other times designers use "Grunge Brushes". Grunge brushes are literally Photoshop and Illustrator brushes in the form of grime, dust and scratches that are applied to images with a pen or a brush tool.

Unfortunately, as of yet Inkscape does not have such versatile brush features as the Adobe suite. This, however, doesn't mean that your graphics are doomed to be sleek and smooth forever.

Methodology

Because Inkscape does not have brushes, we will achieve the same effect by generating paths that look grimy, setting them to the background colour (to make it look like our drawing has had holes made in it), duplicating, rotating and placing the paths on top of our graphic. In this tutorial we will be applying grunge effects to the below graphic:

This is what our grunge paths will look like (remember, they will be the same colour as the background)

We will look at three different ways of generating our dirty/scratchy paths. The methods are in order from least realistic to most realistic:

• Manually drawing and creating grunge paths
• Manipulating L-Systems to create grunge paths
• Generating grunge by vectorizing images

The last approach - creating a highly distorted vector from a picture - is used by Photoshop professionals to create their brushes and gives the most realistic grimy effect.

What makes a good beat-up effect?

There are some criteria that make a good grunge path, keep these in mind as you are manipulating paths and creating that perfect beat-up look:

• The areas of the path need to look random - one part of the path should not look like it is a continuation of another part. This is the main challenge of creating grunge paths, and is very important as a discernible pattern of scratches etc. will make the effect look inauthentic.
• Individual bits of the path should look authentic - your dirt path should not be composed of neat geometric shapes, but of globs and irregular bits.
• Even Sparsity/Density - your path shoul have a uniform distribution of particles. Having a path that is dense at one end and sparse at another makes it difficult to apply to an illustration.

Due to the above considerations we will be applying our grunge paths mostly to the contours of our illustration.
Why?
Because if we stamp the entire brush onto the middle of a shape's surface, it will be easier to see that there is a pattern there and that this is not the organic result of the object being beat up, scratched and aged.