Fix Uneven Solidify Modifier Thickness in Blender

The Solidify modifier in Blender adds depth to 2D meshes, but non-uniform object scales and sharp geometry often cause distortion and inconsistent wall thickness. Achieving a uniform shell requires resetting your object's scale transformations, toggling specific settings within the modifier properties, and adjusting normal calculations for complex corners. This guide outlines the exact steps needed to ensure your mesh maintains a perfectly even thickness across all faces.

Step 1: Apply the Object Scale

Unapplied scale is the primary cause of uneven thickness. If an object is resized in Object Mode rather than Edit Mode, the Solidify modifier calculates offset distances based on stretched axes.

  1. Select your object in Object Mode.
  2. Press Ctrl + A to open the Apply menu.
  3. Select Scale.
  4. Check the Sidebar (N panel) under Item > Transform to ensure the Scale values for X, Y, and Z are set to 1.000.

Step 2: Enable "Even Thickness"

By default, Blender calculates thickness along vertex normals, which causes walls to narrow at sharp corners.

  1. Go to the Modifier Properties tab (wrench icon).
  2. Open your Solidify modifier settings.
  3. Check the box labeled Even Thickness.

This setting adjusts the vertex offsets at sharp junctions so the perpendicular distance between the original and newly generated faces remains equal.

Step 3: Enable "High Quality Normals"

If the mesh contains sharp angles, complex bevels, or irregular vertex density, standard normal calculations may still produce minor artifacts.

  1. Under the Solidify modifier options, locate High Quality Normals.
  2. Check the box to enable it.

This forces Blender to recalculate the face and vertex normals with greater precision, resolving thickness errors on complex topology.

Step 4: Check Geometry and Normals

If unevenness persists after adjusting modifier settings, underlying mesh issues may be the cause:

  • Recalculate Outside Normals: In Edit Mode, select all faces (A), then press Shift + N to ensure all face normals point outward.
  • Remove Inverted or Non-Manifold Geometry: Ensure there are no internal faces or duplicate vertices by selecting all geometry in Edit Mode, pressing M, and choosing By Distance.