I asked this question about two months ago but here it is again.

Is there a list of the current Tartans that are derived from the Black Watch Tartan?

Such as Black Watch with a White over-check. or Black Watch with one white over-check in each full Sett and alternating red over-check.

If my head gets to hurting when thinking about all this I simply turn the fabric 90 degrees and voila, the generic and public Blackwatch Tartan. Simple.

And of course we all know that all Tartans are actually derived from the only true Clan Tartan today. This Tartan is used by the only real and faithful Clan in existence today that holds to the original concept of Clan.

Clan X Marks!