I truly feel flattered, I have been asked for a tutorial how to make this!
It has been a while ago so I hope I got my measurements right, I didn't take photos at the time and I have only tried out one way of making these, but that's what I did:
1. Cut 4 strips each of white and black, 2.5" wide by 20" long
2. Sew them all together, using a 1/4" seam, alternating one stripe of white, one of black etc.
You will end up with a piece of fabric resembling a pedestrian crossing lol, size should be 16 1/2" wide by 20" long. I pressed all seams towards the dark, in retrospect I might have pressed them apart instead.
3. Cut your fabric in 2 1/2" wide strips horizontally. Your strips should now consist of alternating rectangles of white and black.
4. Lay your strips out next to each other. Flip every second one over from left to right so you have one starting with a black rectangle, the next with a white rectangle etc. - the regular chess board pattern.
5. Now you have to offset them against each other before you can sew them. Following the example in DS' Murderous Maths book, I moved every strip starting with a white triangle 3/4" to the left (so rather than matching the seam, my seams are 3/4" and 1 1/4" apart). All strips starting with white should be in the same position, and all the ones starting with black should be in the same position as well.
6. Sew strips together using 1/4" seam in the method of your preference - one after the other, or pairs and then add pairs together. I think I might have done the former, but I seem to recall I flipped it over every other strip, meaning that when you look at the completed piece right side up, one time I would start sewing from the left, next time from the right. It seems to keep the strips from moving too much one way.
7. I decided to applique it to a yellow background, but I only had leftovers to use. Therefore I chose a left-over piece of batting, in this case cotton-bamboo which I really love right now, approx 22x18", and using sew and flip I first attached narrow yellow strips top and bottom, then wider ones left and right to my batting.
8. Using my recently purchased Hera Marker (I can thoroughly recommend this!) I marked a 1/4" seam allowance on the back of my 'wonky' chessboard all around the edges. Now pin this seam allowance to the back (otherwise the squares on the edges are rectangles and I thought that would look odd) and press. Note: If you have pressed your seams apart, it is a lot easier to do this I reckon!
9. Pin baste backing, batting with yellow background and 'wonky chessboard (I tried to centre mine, you could place it anywhere you like). Using grey Aurifill Cotton thread I satinstitched through all layers around all squares.
10. Bind with the method of your preference.
11. Stand back and admire!!