This is not a detailed document on how to use Inkscape in general- there are other resources online for that. It's just enough to format things for K40 Whisperer.

You can possibly use other design software to do your design, as long as it can export to an SVG. Because K40 Whisperer is pretty tightly integrated with Inkscape's SVG files, you may need to open and re-save in Inkscape to get certain properties right.

• 1st Step: Set your document size (shift-ctrl-D)
• If you're just raster engraving, draw or import or whatever into the document. It should be in black/greyscale. Non-black raster colors will probably interpret as black/greyscale?
• Vector engraving: When you have your text or object on the document, select it and go to the Fill & Stroke menu (shift-ctrl-F). Click on the Stroke Paint tab. Select the square next to the X(i.e. Flat Color). Set the Color to 0000FF (full blue). In the Stroke Style menu, the width should be non-zero.
• Vector Cutting: Same concept as above, but set the color to FF0000 (full red).

Gotchas:

• Copying/Pasting vectors on X11-based platforms(Linux/MacOS) causes the vector to be pasted as a raster. Use Duplicate (ctrl-D) instead.

Inkscape/K40 Whisperer on macOS:

This is somewhat tricky to install correctly. It requires a built-from-source version of Inkscape (I used Homebrew, though the version on there has a broken dependency. I then had to hand-apply a patch that hadn't been accepted yet.), and a number of Python libraries. You also have to run it via sudo, as PyUSB can't open the serial port as non-root.