Give a curve thickness

Give a curve a cross-section using bevel depth, resolution, caps or a supported custom profile.

Before you start

Select a curve in Object Mode and open Curve Data. A modestly curved open path makes the thickness and end caps easy to inspect.

Give a curve a round or custom cross-section for a cable, pipe, or trim.

Choose Depth as the bevel mode and increase Bevel Depth from zero until the curve has the intended thickness.
Adjust Bevel Resolution to smooth the cross-section and enable Fill Caps when the open ends should be closed.
For a custom section, choose Object mode in the bevel settings and pick another curve as the profile. Continue editing the path’s control points to change its route.

Controls	What changes
Depth	Controls round-section thickness. A thick section around a tight bend can intersect itself.
Bevel Resolution	Adds cross-section smoothness. Increase it only enough for the intended viewing distance.
Profile object and caps	A separate curve defines a custom profile. Fill Caps closes open ends; it does not automatically create a hollow pipe wall.

Increase Bevel Depth on a curve, compare resolution settings, and inspect the ends with caps on and off.

Inspect end caps, profile orientation, and tight bends. Keep a larger bend radius or a smaller section if the surface crosses itself.

Open the editor and follow the steps with your own scene.