Quote Originally Posted by RockyR View Post
I think I see what you mean... the "dark" sections of BW are 'symetrical in and of themselves while the "sections with the thick black line" in the MacNaughton are NOT symetrical in and of themselves.
Yup, that's what I meant. In reality, you could assign a letter to every single element and represent the tartan as ABCDEFGFEDCBABCDEFG...... (which is essentially what the sett abbreviation is). If you called this an AB tartan, you'd group some of the individual elements (maybe A=A+B+C+D and B=D+E+F+G).

But what if you had a tartan where the elements were BAB CDEDC BAB FGHGF BAB CDEDC

It could be AB, if A= 1/2A+B+C+E+D+C +B + 1/2A, and if B = 1/2A B+F+G+H+G+F+B+1/2A

But it might be more useful to lump a little differently and call it an ABAC, where A= B+A+B, B=C+D+E+D+C, and C=F+G+H+G+F

Wow - is that confusing, or what???