Aug 252018
 

The following best practices for creating and publishing graphics are application-agnostic and can be done in everything from open source software to top-flight, tools-integrated component content management systems. They work in nearly every common output media; and exceptions are noted when they apply. I employ Microsoft ® Windows® OS terminology and keyboard shortcuts, but nearly every other OS has similar shortcuts or tools that accomplish the same effects.

Capturing screen shots

  • Ensure that you are using a ‘classic’ desktop theme with no gradients, glass effects, or other uncompressible effects applied to the window chrome (title bar, borders, scroll bars, title bar buttons).
  • Set your desktop resolution to the highest it can support for ‘version 1’ of the application; and note that resolution so that you can return to it in later versions.
  • Do not use font scaling.
  • If manually configurable, use font smoothing (almost always enabled automatically, in modern OSs).

This approach ensures that your files will compress efficiently and remain consistent year after year, so that you can update screens selectively instead of in toto.

  • For native applications, use Alt+Print Screen to capture only the active dialog.
  • For web-based applications, use a capture application that allows you to capture only the browser viewport.

Both of these methods eliminate the need to carefully crop to pixel precision in your raster-art image-manipulation program.

  • If you must manually crop, do so to a hard, visible edge whenever possible (rather than a whitespace edge).
  • Avoid using ‘tear’ or ‘fade out’ effects when you must crop to whitespace, because they are hard to consistently apply and they greatly increase final file size. Instead, draw a hard, solid line for it in your image manipulation program; and note the line color and weight for later.

Creating line art

  • No matter what vector-art application you use to generate line art (Inkscape, Microsoft Visio®, LibreOffice Draw), shrink your canvas to the drawing contents prior to saving.
  • Save line art as either SVG or PDF.
    • Exception: If you are generating compiled HTML Help, you must export as raster art. If so, rasterize it to 96 dpi (common screen resolution) to avoid scaling issue in the HTML. In that case, save it to PNG.
  • Always save the typeset file using the same file name as the image-manipulation application’s source file name. If necessary, append a suffix to the source and typeset file names to distinguish them, though if you follow the above best practices, the file extension will also distinguish them and make a suffix redundant.

Applying callouts to captured images or line art

  • Create a library of callout objects in your vector-art application.
  • Always use line art and text (which is itself vector art) to make callouts.
  • Gradient and shadow effects might or might not affect final file size, depending on your vector-art image manipulation application. Use at your own risk. Do not use shadows unless the callouts overlap the image.
  • If you are using overlapping callout and lines, use colors that will consistently contrast with the bulk of the application’s colors. Otherwise, you are almost guaranteed to end up needing to use shadow effects or contrast-increasing callout borders (line around line, container or line around text)
  • Do not use words as callouts:
    • Use alphabetic callouts for pointing out image elements that you intend to define in typeset text below the typeset image.
    • Use numeric callouts for enumerating sequences; and if you use a containing shape, make it a different one than the containing shape for defining callouts. Either set these numerals to the step numbers of the task that will refer to them; or use a different type of numeral system (for example, Roman numerals or Greek alphabet) and set them sequentially.
  • Keep those object in linked layers so that you can easily copy all of their layers, paste them into new layers, and edit the text component of the callout.
    • Exception: If you elect to use only text for callouts, without surrounding circles, squares, shadows, or other offsetting effects, then you will not need more than one text layer and, as such, nothing else linked to it.
  • If you intend to have callouts off to the side of the image rather than completely overtop of the image, you have two options, each with its own consequences:
    1. All side callouts must be on the right side of all images, which can quickly become constraining.
    2. Side callouts require additional attention to detail or a typesetting concession:
      • The leftmost edge of left-side callouts must always be an exact distance from the left edge of the image.
      • You must commit to always centering the image when it is typeset.

      Failure to apply one of these two approaches will lead to the effect of your images seeming to ‘randomly’ slide left and right relative to the page margins.

Saving raster-art images without callouts

  • Always save as PNG.
    • Exception: If an output format does not support PNG… first consider going to a different output format; but if not, then save as 100% quality JPG. If you want a smaller file size in final output, post-processing the output file is a better way to compress than ‘ruining’ your source format right out of the gate.
  • Always save the typeset file using the same file name as the image-manipulation application’s source file name. If necessary, append a suffix to the source and typeset file names to distinguish them, though if you follow the above best practices, the file extension will also distinguish them and make a suffix redundant.

Saving raster-art images with callouts

  • See “Creating line art” above, so that the callouts remain vector art (and both SVG and PDF support embedded raster art).