How to Set Brush Dynamic Fade Lengths in GIMP

Configuring custom brush dynamic fade lengths in GIMP allows digital artists to create smooth, tapered strokes that naturally mimic traditional inking pens and pencils. This guide provides a direct, step-by-step walkthrough on how to create a custom paint dynamic, map the fade input to brush size, and adjust the specific fade length within the Tool Options dock to achieve precise tapered line ends.

Step 1: Open the Paint Dynamics Dialog

Default dynamics in GIMP are write-protected, so you must create a new dynamic preset to customize the fade behavior.

  1. Go to the top menu and select Windows > Dockable Dialogs > Paint Dynamics.
  2. In the Paint Dynamics panel, click the Create a new dynamic icon (the blank document icon at the bottom) or right-click an existing preset and choose Duplicate Dynamic.
  3. Name your new dynamic preset (e.g., "Tapered Inking").

Step 2: Configure the Dynamics Matrix for Tapering

Once the dynamic is created, the Paint Dynamics Editor will open automatically.

  1. Locate the Dynamics matrix grid.
  2. Find the row labeled Fade and check the box in the Size column. This forces the brush size to shrink as the stroke progresses based on the fade calculation.
  3. (Optional) If you also want the stroke to become transparent at the end, check the box in the Opacity column under the Fade row.

Step 3: Set the Fade Length in Tool Options

The actual distance over which the brush tapers is controlled directly inside the Paint Tool Options, not the Dynamics Editor.

  1. Select your preferred painting tool (such as the Paintbrush Tool or Ink Tool) from the Toolbox.
  2. Open the Tool Options panel (usually docked on the left or accessible via Windows > Dockable Dialogs > Tool Options).
  3. Under the Dynamics dropdown, select the custom dynamic preset you created in Step 1.
  4. Expand the Dynamics Options section (click the small arrow next to it if it is collapsed).
  5. Locate the Fade Length slider.
  6. Enter your desired fade distance in pixels (or change the unit dropdown to centimeters, inches, or millimeters). A smaller value produces a quick, sharp taper, while a larger value extends the taper across longer strokes.

Step 4: Adjust the Fade Repeat and Curve

To further refine how the taper behaves during continuous drawing:

  • Repeat Options: In the Tool Options under Dynamics Options, adjust the Repeat setting:
    • None: The brush tapers down once and remains at zero until the mouse/stylus is lifted.
    • Sawtooth wave: The stroke continuously resets and repeats the fade cycle.
    • Triangle wave: The stroke tapers down, then widens back up in an oscillating pattern.
  • Custom Curves: In the Paint Dynamics Editor, click the Fade tab at the bottom to adjust the response curve. Moving the curve control points alters whether the stroke tapers gradually (linear), drops off instantly (concave), or maintains thickness before a sharp final point (convex).