Blender Grease Pencil Brush Radius and Sensitivity Guide

Configuring brush radius and pressure sensitivity in Blender’s Grease Pencil allows artists to create natural, dynamic 2D strokes using a drawing tablet. This guide provides a direct, step-by-step walkthrough on how to locate brush properties, adjust stroke size manually or with keyboard shortcuts, toggle pen pressure sensitivity, and customize sensitivity response curves for optimal drawing precision.

1. Enter Grease Pencil Draw Mode

To access brush settings, you must be in the correct interaction mode:

  1. Select your Grease Pencil object in the 3D Viewport or Outliner.
  2. Change the interaction mode in the top-left corner of the 3D Viewport from Object Mode to Draw Mode.

2. Adjusting Brush Radius (Size)

The brush radius defines the thickness of your stroke. You can adjust it using interface controls or viewport shortcuts:

  • Header Toolbar: Locate the Radius slider in the top bar above the 3D Viewport. Click and drag the slider or enter a specific pixel value.
  • Sidebar (N-Panel): Press N to open the sidebar, navigate to the Tool tab, and adjust the Radius setting under the Brush panel.
  • Keyboard Shortcut: Hover your cursor over the 3D Viewport and press F. Move your mouse outward or inward to resize the brush interactively, then left-click to confirm the new radius.

3. Enabling Pressure Sensitivity for Radius

To make your stroke thickness respond to the physical pressure applied by your stylus:

  1. Locate the Radius setting in either the top bar or the Tool settings panel.
  2. Click the Pressure icon (a stylus/bullseye icon) situated immediately next to the Radius slider.
  3. When highlighted blue, pressure sensitivity is active, allowing lighter pressure to produce thinner lines and harder pressure to produce thicker lines.

4. Customizing Brush Pressure Sensitivity Curves

If the default tablet response feels too stiff or too soft, you can calibrate how the brush responds to pressure:

  1. Open the Properties Panel (right side) and switch to the Active Tool and Workspace Settings tab (screwdriver/wrench icon), or use the N sidebar under the Tool tab.
  2. Expand the Advanced or Brush Settings dropdown.
  3. Locate the Pressure Curve (often under the Size/Radius sub-panel).
  4. Click and drag the points on the curve graph:
    • Convex Curve (arced upward): Makes the brush reach full thickness with lighter pressure.
    • Concave Curve (arced downward): Requires firmer pressure before the stroke reaches maximum thickness.

5. Adjusting Global Tablet Sensitivity

If you want to alter pressure behavior across all brushes simultaneously rather than on a per-brush basis:

  1. Go to the top menu and select Edit > Preferences.
  2. Select the Input tab from the left sidebar.
  3. Under the Tablet section, adjust the Pressure Sensitivity or Threshold settings to globally calibrate Blender to your specific tablet hardware.