Measuring diagonal wobble

I measure diagonal wobble using a simple procedure


Diagonal template image - a standard PNG file created with using Adobe Illustrator. This provides visual guides that make it easier for the testing. Image is shown later in this doc.

Ruler - I use a simple plastic ruler. I do not use metal rulers because they might interfere with the EMR tech in the pen.

Driver - I use the latest manufacturer driver. For very old tablets that don't have recent drivers, I use OpenTabletDriver.

Application - Krita

Testing process

  • Verify the plastic ruler has no rough spots or bumps that would affect the measurement. It should be smooth.

  • Tablet configuration

    • For pen tablets, set the active area to a single display.

    • For pen tablets, set the driver to match the aspect ratio of the tablet to the display.

  • App configruation

    • Load the diagonal template image

    • Set Krita zoom to 100%.

    • Set Brush to Ink-2 Fineliner with default brush settings and set size to 5 pixels.

  • Drawing

    • The template requires 3 sets of lines drawn at different speeds - 3 lines for each speed

    • Draw the line from the lower left to the upper right.

      • Follow the specified speed as much as possible

      • pen tilt = about 30 to 40 degrees from vertical.

  • Save as a PNG

Evaluation wobble (DRAFT)


  • MAGNITUDE - how wobble is physical displaced from "center" of line.

  • VELOCITY - Is wobble visible in slow, medium, fast strokes


  • VERY LOW - Strokes easily confused for a perfectly straight line

  • LOW - lines mostly straight with occasional and minor wobble

  • MEDIUM - moderate Wobble visible in majority of lines

  • HIGH - moderate wobble available in lots of lines

  • VERR HIGH - lots of wobbling in lines

Wobble testing template image

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