Scarface - Creating a scar n stitchmark on a face

Start by opening an image of a face. The more focussed an image, the better.

Using lasso tool create a selection of that area you want to make scar.

From layer pallete enable preserve transparency ( first icon on top of layer palette ).

From filter menu select noise>>add noise.
Use noise settings as shown.

From filter menu select brush strokes>>crosshatch.

 

Apply crosshatch settings as shown.
Disable preserve transparency form layer pallete and from filter menu apply blur>>gaussian blur.
Use gaussian blur settings as shown.
Create a new layer. Using brush tool make some reddish dots around the scar.
Using brush tool join these dots to create an illusion of stitches. Use some light color like white or pale white to create stitches.
Change the color mode of stitch layer to soft light.

 

A scar with some stichmarks is created on a face.