Yes there's already a "Cornish National" tartan... I think it is hideous. De gustibus non est disputandum.

Here it is in all its glory:



To my eye it looks even worse when made up into a kilt, if you can imagine it.

Now, what does the would-be designer of a "Cornish tartan" have to work with? The two symbols are the flag of Saint Piran, a white cross on a black flag:



and the "bezants", fifteen gold circles often (but not always) arranged on a black shield:



Due to the nature of tartan the bezants must become squares, and the number must decrease to 9 or increase to 16. The St Pirin flag, why, tartan design is all over that one.

Seeing that the shield is black, and the flag is black, I drew up an all-black tartan with four yellow lines and one fat white stripe. It was awful.

I realised that the black background of the bezants and the black flag needed to be set off by a background of some sort. Well, Cornwall is surrouned by the sea and sky so why not a nice bright blue? Here's the result:



That looks a bit stark, a bit diagrammatic to me, so I tried introducing a motif to break up the big blue area. Here's what it looks like, rendered in various hues:









What do you all think? Best to have the stark simple one? Or if the extra stripes are added, which looks best? Thanks!