I'm pretty sure it's what Leslie said - that that's what you asked us.
The reason is that it takes a little while to eye-ball the joining point
on a non-45 diamond. The seam allowance seems to go on such a long way
after the point. You could make a 'corner' from thinnish card which you
could place at a quarter inch from each side and put a dot at its point.
You would have to do two, to cope with the two angles in your diamonds.
I think I remember that they were 60 diamonds? If you measured the
distance at first, then got used to the placement, it would save you
loads of time. I used it successfully for several pieces. In fact I
made, for differently angled diamonds.
>I have one last border to put on the disappearing nine-patch, then I
>will go back to my diamonds. I remember that I am supposed to draw a
>line 1/4" from each edge. But - I don't remember why. Now I ask you,
>how pathetic is that! And now I also ask you, why am I doing that?
>Karen, Queen of Squishies
pat on the hill