Thanks! What I meant by base, wasn't bottom of the letter, but where the entire outer 'outer'-edge of the letter joins with the field, which you wouldn't see in a 2d picture, if you know what I mean? The reason I persist in this point is some of the pictures I've seen of round-backs are sometimes 'flecked' for want of a better word, whereas the angle-backs are mostly really triangular behind. I completely get your perspective on this, using the diagrams and plates, but it leaves me still somewhat confused and unconvinced. There appears to be an inbetween state, which buggers things re a simple classification?