20.10.20265 min

Blender UV Unwrapping: Seams and Stretching

For a texture to sit evenly on a Blender model, check the object scale, mark seams and run Unwrap. Inspect the result with a checker texture: elongated squares reveal distortion, while differences in square size help expose uneven texture density. This sequence is useful for furniture and decorative objects in an architectural scene.

Prepare the model and a test texture

A UV map links points on a surface to coordinates in a flat image. Seams define where that surface can open into separate pieces called UV islands. The model's geometry stays intact.

Apply the object's Scale before unwrapping. Create a material with an Image Texture for testing: click New and choose UV Grid as the generated image type. Connect it to Base Color and switch to Material Preview. The UV Editing workspace lets you compare islands on the left with the model on the right.

If selections do not match between the editors, check UV Sync Selection. You can use Reset to clear a primitive's existing map for practice; in a production project, preserve any UVs you still need first.

Mark seams and run Unwrap

Enter Edit Mode and edge selection mode. Select the edges for your cuts and use Mark Seam. Select the relevant faces, open the U menu and run Unwrap with the Angle Based method.

A cube shows why a single short seam may be insufficient: the map lacks room to open and parts of the surface collapse. Add seams progressively and inspect how the UV mesh changes after each attempt.

Place seams on less visible areas where possible. On a complex shape, an extra cut can be more useful than a large continuous surface with stretched texture. Select an edge and use Clear Seam to remove an unhelpful mark.

Collapsed cube UV map and checker texture in Blender — A cube with insufficient cuts: its UV mesh has collapsed near the image edge. 00:03:57

Separate a cylinder into its side and end caps

A cylinder is a useful way to understand seams on furniture legs and other elongated parts. Separate the top and bottom caps with seams along their boundaries. Add a longitudinal seam on the side and run Unwrap again.

The side opens into a flat strip and the caps become separate islands. Compare this with the cylinder in the screenshot: it is easier to control than placing the entire closed surface in a single piece.

Live Unwrap is available in Options. It updates the map as seams change, making alternatives quicker to inspect. Continue checking the squares on the actual model after every edit.

Blender cylinder UV layout with separate end caps — The cylinder is unwrapped into a side strip and two caps; Live Unwrap is enabled. 00:04:40

Inspect distortion on a complex shape

Suzanne reveals issues that also occur on curved or protruding model parts. If squares are large on one part but small or elongated next to it, examine the seams and the size of those UV regions.

Enable UV Stretch. In the displayed mode, blue regions have less distortion, while green and yellow help identify trouble spots. The color overlay helps locate problems; the checker texture shows how they affect the surface.

Try separating protruding parts partially or completely. Add a seam near a region that cannot open cleanly, then unwrap again. Complex rounded shapes require a balance between seam count and acceptable distortion.

UV Stretch color overlay and checker-textured Suzanne — UV Stretch reveals different distortion levels across Suzanne. 00:06:36

Resolve overlaps and pin reference points

Inspect the islands in the UV Editor. Overlapping regions use the same part of the image. When painting a texture yourself, that can repeat the same marks on different parts of the model.

Move selected UV points or islands with G. For a local adjustment, pin reference points using Pin, shortcut P: pinned points turn red. Edit the required area while watching neighboring polygons and the checker pattern.

Avoid fixing one distortion by creating another. Changing an island's size affects texture density; compare the checker on the model again after moving or scaling it.

Close-up of Suzanne's UV mesh and model in Blender — A close view of the UV mesh and checker pattern helps inspect local edits. 00:07:55

Check the UV map before applying the final material

Compare checker density mainly on surfaces that will be visible in the final view. Identical image resolution does not guarantee equal sharpness on different models: the space allocated to each surface in the UV map matters.

Once the map no longer causes noticeable distortion, apply the production textures. If a defect remains in one area, return to its seams and island; changing the material will not repair the UV layout.

Check that the object scale has been applied.
Compare square shape and size on neighboring areas.
Remove unintended island overlaps.
Inspect seam visibility and save the reviewed map.

Questions and answers

Why does the texture stretch after Unwrap?

Check the object scale and seam placement. A closed or complex region may need more cuts to open. Add a seam, run Unwrap again and compare the squares.

Must every seam be hidden?

Less visible areas are convenient, but a complex shape may require a visible cut. Inspect it from the production view and compare it with the distortion that would occur without it.

Why is the same texture sharp in some areas and blurry in others?

UV density may differ between parts. Compare the test squares and how much UV space the surfaces occupy. Avoid random island scaling after your checks.