This one is almost ready to sew up and I  thought I’d document a couple of steps with pics –

1) Showing the back/inside of the structure, where knots anchor the thread as it goes to the front.

2)  Three of the triangles sewn together to provide the one working surface.

3)  When the stitching is finished, the final side seam is closed and the base sewn on.

I have done several now, and am enjoying making them.  In the next group I will do surface design before covering the template pieces, to see how that goes – probably some combination of paint and stitch – ideas for which are coming far faster than my ability to make them!  I may have some thinner batting somewhere and may replace batting with a couple of layers of cotton fabric – I learn something or tweak a detail on each one, but this is probably the last how-to on them, though  I have no idea where this 3D quilted textile art will go from here.