Yesterday I organized my fabric into eight sets of three groupings – light, medium, dark. I cut 2″ strips from each and cut the trapezoid shapes (16 from each fabric) plus the small dark triangles for the centre of the block. (In a couple of blocks I ran out of fabric and had to fill in a couple of trapezoids with as close a colour match as I could – it will be interesting to see where they show up in the layout).

Next step was to group these trapezoids into groups of three for each block (a dark, a medium, a light). Before I did that I spent quite a bit of time looking at photos of the the quilt in progress which I found online in order to sort out the groupings. Then I set up the blocks – two sets – one which starts with the triangle on the right side of the light piece; the other with the triangle on the left side of the light piece.

These are the blocks with the triangle on the right. There is a complementary set with the triangle on the left.

In the afternoon I stitched block “A”, then block “B” and placed them together so the dark fabric forms the wide 120° angle – the two triangles at the bottom of the stack below. I also did the “C” stack but that triangle fits in somewhere else.

The next triangle needed to join the light vertical on the “B” block turned out to be block “M” followed by “L”, then “K”.

To see how this array would look like sewn together I stitched one of each together.

You can’t really see the optical illusion yet – I need to construct the second column and join it to column #1. At the moment I’ll continue constructing all the blocks then lay out the first column (it uses all 16 triangle blocks). I don’t yet know where the second column actually begins – the order of the blocks will be the same, but it will start at another place and until I get all the blocks stitched, I’m not going to know where column #2 begins.

In any case, I’ve set up a chart showing the fabrics in each triangle block – there are no duplicates, but the linkages become apparent. It will be a matter of just laying out the matching pieces to create the structure of the interlocked elements.

Now, it’s just a matter of carrying on with block construction. I’ve got six block sets done – that leaves a dozen to go and then I can set up the columns….