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
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
Considerations
MAGNITUDE - how wobble is physical displaced from "center" of line.
VELOCITY - Is wobble visible in slow, medium, fast strokes
Scale
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
