Chalk It Up

 

Image ref (crop of this image that I took last fall):  http://justpaste.it/files/justpaste/l1000048.jpg

 

Tools:

 

GIMP:  http://www.gimp.org

G'MIC: http://gmic.sourceforge.net/

 

Very simple flow to create this render.  Click on small preview step images to see the full rez view.

 

1.   Run G'MIC Paint preset:

 

 

2.  Run Neon Edge Detect filter; play with sliders to taste:

 

 

3.  Create a solid black fill layer on top of your result thus far, reduce opacity to 50%, and set the result to Dissolve:

 

 

4.  Pretty much through, but to brighten it up to look more like a chalkboard would be cool; up the saturation too.

 

 

We are done; click image below for the render (yes, I did add a border but not going to create the tut for that).    :)