UE4 – Blending materials using Paint

Software:
Unreal Engine 4.24

To blend materials or material properties using Paint:

1. Create a material that blends 2 materials or material properties using a texture as a mask like this example.
2. Assign the material to an object in the level map and select it.
3. In the Editor’s Mode window,
   Select Paint mode, choose the Textures option.
4. In the Brush settings, set brush Radius, and Strength.
5.  In the Texture Painting settings, choose Paint Color and Erase Color.
   * These will usually be white and black, but that depends on how the mask texture is used (a single texture can be used to provide 3 different effect mask using RGB channels)
6. in the Paint Texture property select the material’s mask texture you wish to paint.
   
7. Paint using Paint Color using LMB strokes,
   Press Shift while painting to paint using Erase Color:
   
8. When finished, hit Save and Apply:
   

Note:
As far as I know, there’s no way to create a new empty or solid colored texture in UE4,
So we have to import a texture to be able to paint it in the Editor.

>> The scanned PBR materials in demonstrated in this post are from Texture Haven (texturehaven.com)

Related:
Blending materials