Just for clarification, Black Isle tartan and Black Shadow tartan are not the same. Black Isle actually has a tartan pattern made up of black and extremely dark charcoal threads that has a standard smooth tartan material surface, while shadow tartan seems to be made up of all black threads of different weights or at least different textures, so the color is all black but the tartan pattern is made up of differences in the surface texture and luster of the fabric. Black Isle only comes in one colorway, but the shadow tartans come in at least a handful of colors.

Sorry for the thread jack.