Texturing & materials · Beginner

UV seam

An edge marked as a cut line, telling the unwrap where to split the surface

Also called Seam, Mark Seam

What is a UV seam?

A UV seam is an edge you mark as a cut line, telling the software where to split a model’s surface when it unfolds it flat for texturing. Seams decide the shape of each flat piece, so good placement means less stretching. In Blender, seams show as red edges in Edit Mode.

Think of it like this

Like the seams on a pair of jeans: they mark where flat fabric was cut and sewn, and a tailor tucks them where they are least visible.

Where it fits in a 3D project

  1. Create
  2. Surface
  3. Rig
  4. Animate
  5. Render
  6. Export

Surface: Giving the shape its color and material: UVs, textures and shaders.

3D modelUnwrapFlat UV layoutSame face
Unwrapping lays each face of the model flat, so a 2D texture can wrap back on.

How a UV seam works

  1. 01In Edit Mode, select edges along natural breaks or hidden areas.
  2. 02Choose Mark Seam from the UV menu, opened with U, or from the Edge menu.
  3. 03Unwrap; each area enclosed by seams unfolds as its own flat island.
  4. 04Check with a checker texture and move seams where stretching shows.

UV seam vs UV unwrapping

PropertyUV seamUV unwrapping
What it isA cut line you markThe step that unfolds the surface
WhenBefore unwrapping, edge by edgeAfter seams, in one command
In BlenderU > Mark SeamU > Unwrap
ControlsWhere islands splitHow the flat pieces come out

Seams are the plan and unwrapping is the cut: mark seams first, then unwrap, and repeat until the islands lie flat.

Where a UV seam is used

  • Splitting a character into head, body and limb islands
  • Hiding cuts under arms, along inner legs or behind hair
  • Opening a box, bottle or pipe into flat pieces

Beginner tip

Mark seams where the eye rarely looks and where the shape already breaks, such as hard edges, the backs of objects and under overlaps. Each seam can show a faint texture line.

Terms related to a UV seam

UV seam FAQ

How do I mark a seam in Blender?
In Edit Mode, switch to edge select, select the edges, press U and choose Mark Seam. The edges turn red. To remove one, select it and choose Clear Seam from the same menu.
How do I hide UV seams?
Place them where people seldom look, keep busy texture detail away from them, and paint across them on the 3D model rather than on the flat layout. Enough padding between islands also stops thin lines from showing.
How many UV seams should a model have?
As few as keep every piece flat with little stretching. Too few and the surface distorts; too many and you get lots of small islands and visible joins. A plain cube needs seven cut edges to unfold.
Do UV seams change the 3D model?
No. A seam is only a label on an edge. The mesh keeps its shape and stays joined in 3D; the split happens only in the flat UV layout.

Updated October 29, 2026 · Browse all 3D terms