Add Controlled Thickness to Mesh Surfaces with Blender Solidify Modifier

What will you learn in this guide?

Blender’s Solidify Modifier adds thickness and depth to a mesh surface. In this guide, you’ll learn how to add the modifier to an object, choose between Simple and Complex modes, and evaluate settings such as Thickness, Offset, and Boundary. We’ll also cover factors that can affect the result, including non-uniform scale, surface normals, and modifier stack order.

Blender modifiers affect an object’s appearance and the form evaluated for rendering without directly changing its base geometry. An object can have multiple modifiers, which are calculated in sequence. Keeping this flexibility while adjusting Solidify makes it easier to compare different results. Applying a modifier converts its result into actual geometry and removes the modifier from the stack.

Requirements

• You need a mesh object to work on and Blender. The source guides do not specify a particular Blender version number.

• The guides do not mention any hardware requirements or account requirements for this operation.

• Before you begin, check the object’s scale and surface normals. Non-uniform scale can cause thickness to vary in different directions.

You can add Solidify to the active object using Add Modifier. Alternatively, use the add button at the top of the Modifiers tab in the Properties Editor, or press Shift-A in the same tab. New modifiers are added to the bottom of the stack, so they are calculated after the existing modifiers.

How to use Solidify Modifier

1. Add Solidify to the mesh. Make the object you want to work on active, then add the modifier using one of the methods above. Its options will appear in the modifier panel. Keep in mind that its position in the stack can affect the result: Blender evaluates modifiers from top to bottom.

2. Adjust Thickness and Offset. Thickness determines the depth added to the surface. Offset controls which side of the original surface the new geometry is placed on, with values ranging from -1 to 1. At an Offset of 0, the result is centered around the original surface. Surface normals help determine the inward and outward directions.

3. Choose between Simple and Complex modes. Simple thickens the geometry using a basic extrusion approach. It does not work if more than two faces are connected to an edge; it may also fail to create boundaries when the normals of adjacent surfaces generally point in different directions. Complex can handle a wider range of geometry and can be used for shapes that Simple cannot handle, such as architectural wall layouts. The guide recommends choosing the faster Simple mode unless there are unusual geometric conditions.

4. Evaluate the thickness method in Complex mode. Fixed keeps new points at a fixed distance from the original points. Even aims for more consistent thickness at sharp corners, but may not always succeed where more than three faces meet. Constraints offers a more advanced solution and guarantees the most appropriate thickness in cases with up to three faces. This option does not promise perfect results for every possible mesh.

5. Choose how open edges are finished. The Boundary setting controls the appearance of opening edges. None applies no additional correction. Round shapes the opening edge inward, while Flat gives a planar opening a flat finish. Compare these options based on how the model will be used.

6. Check scale and normals. Solidify calculates thickness from local vertex coordinates. If the object has non-uniform scale, thickness may appear different in different directions. The guide recommends applying or clearing the scale to address this. If boundaries do not form in Simple mode, also check the direction of the surface normals and the number of faces connected to each edge; try Complex if necessary.

7. Use additional options only when needed. Rim – Fill creates faces and edge loops between the inner and outer surfaces; turning it off can reduce calculation time if you don’t need them. Even Thickness in Simple mode attempts to account for sharp corners. High Quality Normals can improve some results; both options may require additional computation. Decide whether to use them based on the model’s actual result.

8. Check the stack before applying. If you’re using Solidify with other modifiers, change their order and inspect the result. Applying a modifier that isn’t first in the stack may apply it as if it were first, producing an unwanted result. Use Apply if you need to turn the result into permanent geometry; leave it unapplied if you want to keep an editable modifier stack.

Common issues

Thickness varies in different directions across the model: Check the object’s scale. Calculations in local coordinates and non-uniform scale may be causing the variation. As the guide recommends, consider applying or clearing the scale.

Boundaries don’t form correctly in Simple mode: Check how many faces are connected to each edge and the direction of the surface normals. Simple does not work on edges where more than two faces meet; incompatible normals can also prevent boundaries from being thickened. Complex may be more suitable in these cases.

Thickness at sharp corners differs from what you expected: Try Even Thickness or High Quality Normals, but note that these options may require more computation. The result also depends on the mesh topology. Don’t assume thickness will be exact and consistent, especially where more than three faces meet. Constraints in Complex mode attempts to find a better solution, but does not guarantee perfection in every case.

Opening edges don’t match the model: Compare the Boundary options based on the shape of the opening. Also consider whether you need the additional faces created by Rim – Fill; turning it off can reduce processing time if they aren’t needed.

What does it offer for architectural and visualization workflows?

Solidify can add thickness to architectural elements modeled as surfaces. Architectural wall layouts are among the examples the guide says Complex mode can handle. Leaving the modifier unapplied helps preserve the base mesh while you adjust settings. Simple may be the faster choice for straightforward geometry; when intersections become more complex, weigh the flexibility of Complex against its longer calculation time.

For interior design and archviz projects, check the geometry as well as the appearance: thickness can vary depending on mesh topology, and scale and normals can affect the result. It’s also important to check stack order in scenes that use multiple modifiers. The source guides don’t specify particular hardware or Blender software licensing requirements. However, the guides themselves are published under the CC BY-SA 4.0 license; this is not the same as the license terms for Blender software.

Next steps

Start with a simple mesh and change the Thickness and Offset values to observe the direction of the resulting geometry. Then compare Simple and Complex on the same model and see how the boundaries and corners are affected. Finally, if you’re using Solidify with other modifiers, change the stack order and check the result. Apply the modifier only when you need permanent geometry.

Source and license

This guide has been translated and adapted from the “Solidify Modifier” and introduction to modifiers pages in the official Blender manual. Both sources are published under the CC BY-SA 4.0 license.