The Thickness Tool

The Thickness tool changes the body generated around a skeleton without requiring you to edit both outline edges separately. Use it to create swells and tapers, shift a stroke from one side of its path to the other, or vary a Power Brush nib along its path.

The Thickness Tool

Press 8 or choose Thickness with a Stroke, Power Stroke, or Power Brush element active. Its controls follow the skeleton nodes. For strokes, white controls indicate the element default; local side controls are blue on the right and green on the left, relative to contour direction. A local value overrides the default at that node.

Click a control or marquee-select several. Check whether one side or both are selected before dragging. The Node panel and widget also offer numeric node-thickness controls; assigning thickness to an element without a stroke creates one in its fill color.

Local overrides

Select a control and press Backspace to remove its local override. Shift-Alt-click promotes a local value to the element-wide setting. A global change can affect existing local values: the Stroke panel's Proportional setting governs suitable proportional scaling; otherwise a difference can be added. Inspect the result rather than assuming every override retains its absolute value or ratio.

For another modulation location, insert a skeleton node with the Knife tool. A node used only for thickness can use X-Servant and Y-Servant so it follows neighboring primary nodes; recall Editing Modes and Modifiers.

Numeric thickness

Hover over a control, click its editable on-canvas thickness value, and enter a number. This local editor is separate from the panel's global thickness field.

The compact thickness widget reports the current measurement while you work on the stroke.

The editor also accepts the suffix of a stroke. parameter: n reads the current value of stroke.n. It stores a number, not a live expression. The parameter system is taught in Expressions and Parameters.

For several stroke controls, select the destination controls and Alt-click an existing control to copy its side value. Set that source numerically first if needed. One hovered numeric entry does not imply a change to every selected control.

Snapping and scope

Thickness drags can use enabled Snap and Suggest targets. For snap-free stroke movement, use Control; on macOS, physical Control is the unambiguous route. Contour-lever settings govern fine response. Power Brush handles give Control an additional element-wide meaning, so check the handle type before using a modifier. Read the resulting local values and compare the outline after each adjustment.

Modulating Strokes

A stroke has independently adjustable sides. Start with a uniform stroke, then add local changes where the design needs them.

Gesture on a stroke thickness control	Result
Drag	Changes the local thickness on that side.
Alt-drag	Changes the local thickness on both sides symmetrically.
Shift-drag	Changes the element-wide thickness and distribution from that side.
Shift-Alt-drag	Adds thickness to one side and subtracts the same amount from the other at that node, preserving the total.

For a taper, use local controls near an endpoint and farther along the path. Reduce the end value while retaining the body value, then inspect the transition between them. Add another skeleton node only if the existing locations cannot describe the transition you need.

For a stroke whose ink should move sideways without becoming heavier, use Shift-Alt-drag. The skeleton remains where it is while the stroke is redistributed around it. Check both edges and the resulting counter rather than judging only the side being dragged.

Shift-drag has element-wide scope, so it is not interchangeable with that local redistribution. It can affect other nodes and their overrides through the current global-thickness behavior. Use the local gesture when only one region should change.

These controls apply to both simple strokes and Power Stroke. The distinction remains that Power Stroke also exposes its generated virtual outline to editing aids such as snapping.

Modulating Brushes

For a Power Brush, the local object is the nib, shown as an ellipse at a skeleton node. You can vary its major-axis size, minor-axis ratio, and angle. The Brush panel supplies the element-wide defaults; a local edit overrides them at that node.

Read the nib handles

The size handle on one end of the major axis changes local nib thickness symmetrically. The opposite major-axis handle controls direction as well as size: dragging it around the center changes the angle, while moving it nearer to or farther from the center changes the nib's span.

The side handle on the minor axis changes roundness, shown as a percentage of the major-axis size. A smaller percentage makes a narrower nib with stronger contrast; a larger percentage makes it rounder. The angle readout is in degrees.

Use the ordinary size handle when you want to change weight without changing the nib's direction. Use the angle handle when the pen should turn along the path. Use the minor-axis handle when the contrast should change independently of the major-axis size.

Make local and global changes deliberately

Drag the size handle to change the node's thickness on both sides. Shift-drag that size handle promotes the size change to the element-wide brush setting. Existing local overrides can continue to differ, so inspect them afterward.

Drag the angle handle without modifiers for a local direction change. Hold Shift to snap that angle to 10° increments. This handle also changes its major-axis span according to the pointer's distance from the center; check the size readout after turning it.

Drag the minor-axis handle for a local roundness change. On the angle/size and roundness handles, Control-drag applies the corresponding setting to the element-wide brush. Use the Brush panel instead when you want to set the global nib without relying on handle modifiers.

The angle and percentage labels identify the current geometry. Use the handles for those local settings; they are not the same editable thickness field used for numeric size entry. The local thickness readout accepts numeric size values and the stroke. shorthand.

To remove a local nib variation, select its control and press Backspace. The node returns to the element's size, angle, and roundness. After changing the panel's default nib, inspect existing local variations and reset the nodes that should follow the default again.

Begin with a uniform brush profile when learning these controls, then add local variation. Compare the rendered outline as well as the ellipse: changing a nib's angle or roundness can alter contrast, joins, and counters even when its maximum size stays the same.

Per-node nib editing belongs to the live Power Brush construction. A completed Simple brush gesture has already become ordinary contours; reshape those contours directly or return to a saved live construction if you need nib-level editing.