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Blender Mark Seam Hotkey & Workflow (Updated for Blender 4.x)

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    Sparrow Hawk
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Properly UV unwrapping your 3D models is essential for good texturing, and marking seams is the first critical step in this process. Seams tell Blender how to "cut" your 3D mesh so it can be flattened into a 2D UV map. Without well-placed seams, UV unwrapping can result in stretched, distorted, or unusable UV layouts.

This guide will clarify the hotkeys and menu options for marking seams in modern versions of Blender (including the Blender 4.x series).

Why Mark Seams?

Imagine trying to flatten an orange peel without tearing it – you'd need to make some careful cuts. Marking seams in Blender is analogous to this. You select edges on your model that will define where these "cuts" occur during the UV unwrapping process. This allows Blender to lay out the different parts of your mesh (UV islands) in the 2D UV editor with minimal distortion, making it much easier to apply textures accurately.

Marking Seams in Blender: Hotkeys and Menus

When in Edit Mode with edges selected, you have a few primary ways to mark them as seams:

  1. Edge Menu Hotkey (Ctrl+E):

    • Select the edge(s) you want to mark as a seam.
    • Press Ctrl+E to bring up the Edge menu.
    • Select "Mark Seam" from the list. Marked seams will typically turn red in the viewport.

  2. UV Mapping Menu (U key):

    • Select the edge(s).
    • Press U to open the UV Mapping menu.
    • Select "Mark Seam".

  3. Viewport Header Menu:

    • With edges selected, go to the 3D Viewport header.
    • Click on Edge > Mark Seam.

  4. Context Menu (Right-Click by default):

    • In Edge select mode, select your desired edges.
    • Right-click to open the context menu.
    • Select "Mark Seam". (This is often the quickest way if you're already in edge select mode).

To remove a seam, you would use the same hotkeys/menus and select "Clear Seam" instead.

Visual Cue: Marked seams are highlighted (usually in red, depending on your Blender theme and settings) in the 3D viewport, making it easy to see where you've defined the boundaries for UV unwrapping.

If you're not happy with your seam markings, you can always undo the action by pressing Ctrl+Z. Once your seams are correctly placed, you can proceed to unwrap your model by selecting all faces (A in Edit Mode) and then pressing U > "Unwrap".

(The linked video provides a visual guide to the process of marking seams and UV unwrapping.)

Key Takeaways:

  • Marking seams is fundamental for clean UV maps.
  • In Edit Mode, select edges and use:
    • Ctrl+E (Edge Menu) > Mark Seam
    • U (UV Mapping Menu) > Mark Seam
    • Edge Menu in Viewport Header > Mark Seam
    • Right-click Context Menu > Mark Seam
  • Experiment with seam placement to minimize texture stretching and make your texturing workflow smoother.