User:Thijshijsijsjss/Pen Plotting Panache/Plothatching Workflow

A documentation of my workflow for making multicolor crosshatching plots.

Image preparation

Passe Partout

Eventually, we'll need to create vector paths out of the images the crosshatching software outputs. As plotting is a lenghty step, any preparations we can do to improve the plotting time, will reduce the overall time it takes to create a plothatched image. One such improvement is the way the vector paths are traced. In Inkscape, 'Centerline (autotrace)' has the best results, by far. However, it will often (~60% of the time) crash Inkscape, in which case one has to resort to less efficient tracing methods that will typicially cause each line to be drawn from it's center (effectively adding >50% extra plotting time).

By adding a white border, a 'passe partout', around your image, Centerline (autotrace) has a better chance to succeed. In fact, borders of 100px have had a 100% success rate for me (n>150). This will NOT affect the final dimensions of your plot.

1. Open your file in Krita
2. Go to Image > Resize Canvas
3. Add 100px to the smallest of your image's dimenstions
4. Click OK
5. Save image (overwrite it)

Layer separation

We will separate the different color channels and save them as individual files, so that we will be able to plothatch them individually.

1. Open your file in Krita
2. Change color space to CMYK
   1. Image > Convert Image Color Space
   2. Choose Model: CMYK / Alpha
   3. Click OK
3. Separate image
   1. Image > Separate Image
   2. Click OK
4. Invert all layers. For each of the layers:
   1. Go to a layer and press ctr+I
5. Save layers 'cyan', 'yellow', 'magenta' and 'black' separately. For each of the layers:
   1. Toggle visibility for only one of these layers
   2. Save (ctr+shft+S)
6. Fix opacity. For each of the new images:
   1. Open the image with the Windows default images app
   2. Three dots > Change image size
   3. Save image (overwrite it)