Map Pen Speed to Gradient Colors in GIMP

In GIMP, dynamically shifting through a gradient using pen speed requires configuring a custom dynamic preset where the Velocity input controls the Color output. Because default dynamics presets are locked, you must create a new dynamic preset or duplicate an existing one to access editable matrix checkboxes in the Paint Dynamics Editor. Once the Color-Velocity intersection is enabled, selecting an active gradient in your brush tool options causes rapid strokes to trigger color changes based on movement speed.

Step 1: Create an Editable Dynamic Preset

GIMP’s default dynamic presets are read-only. To unlock the settings:

  1. Open the Paint Dynamics dockable dialog via Windows > Dockable Dialogs > Paint Dynamics.
  2. Click the Create a new dynamics button (the blank page icon) or select an existing preset and click Duplicate this dynamic.
  3. Name your new preset (e.g., "Speed Gradient"). This automatically opens the Paint Dynamics Editor.

Step 2: Configure the Paint Dynamics Editor Matrix

The Paint Dynamics Editor displays a grid with brush attributes on the left and stylus/mouse inputs along the top.

  1. Locate the Color row on the vertical axis.
  2. Follow the row across to the Velocity column.
  3. Check the box at the intersection of Color and Velocity.

When this box is active, stroke speed dictates the sampling point along the gradient. Slower speeds sample from one end of the gradient, while faster speeds advance toward the opposite end.

Step 3: Fine-Tune the Velocity Response Curve

To adjust how sensitive the color change is to your physical hand speed:

  1. Below the matrix in the Paint Dynamics Editor, select the Color tab (or check the dropdown menu for mapped curves).
  2. Choose Velocity from the input selector.
  3. Click and drag the curve line to adjust the transition slope:
    • A steep upward curve causes the color to shift dramatically with slight speed increases.
    • A flatter or diagonal curve ensures a smooth, gradual transition across the full range of movement.

Step 4: Configure the Brush Tool Options

For the dynamic to take effect on the canvas, your active painting tool must be set to read gradient data:

  1. Select the Paintbrush (or chosen paint tool) and open the Tool Options panel.
  2. In the Dynamics section, select your newly created preset.
  3. Scroll down to expand the Color Options section.
  4. Choose the gradient you want to apply from the gradient selector.
  5. Set the Repeat setting (such as None, Sawtooth, or Triangular) to determine whether the gradient resets, loops, or ping-pongs when you exceed the mapped speed threshold.