A blender node, with the blending ratio driven by a B/W image map could do the trick. You can use grayscale too. The color math trick also works. And if you don't have a grayscale image, just run it throug ah Math node (Add, first argument set at 1.000, second argument set at 0.000) to make it grayscale. If it is just adding a seam to stockings, you can simply use the stockings transmap and the seam transmap, and combine the maps using a Math_Add node. Real layered textures are not supported. But you can get the same effect with blender nodes driven by B/W masks.

The pen is mightier than the sword. But if you literally want to have some impact, use a typewriter

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