I recently completed this baby quilt for my newest nephew, Connor. His mom, Lisa, is a high school math teacher, and the whole family is pretty nerdtastic, so I indulged in a bit of math geekery in the piecing design and quilting. I wanted to do something with prime numbers, and the Ulam Spiral lends itself naturally to a quilt. Briefly, the Ulam (or Prime) Spiral is a diagram of the prime numbers when drawn in a grid, starting with 1 in the center and spiraling outwards counterclockwise. The neat bit is that if the spiral is big enough, diagonal lines (primes aligning) begin to appear. Check out this site for a great description and illustrations of the Ulam Spiral. Fittingly for me, Stanislaw Ulam is said to have discovered the spiral’s pattern while he was doodling during a boring meeting.

Starting in the middle of the quilt is 1 (despite being divisible only by 1 and itself, 1 is not a prime, I learned), and moving counter-clockwise, each print fabric represents a prime number, and the solids represent non-primes. To the casual observer (including myself, before I started this project), it probably looks arbitrary, especially with the mix of solid colors used for the non-primes (had they been all one color, the prime number prints would be much more obvious). I offered a hint by quilting the classic Ulam Spiral on top of the quilt: at each prime (and 1, to provide a starting point) I free motion quilted a squiggly dot before continuing the quilting around the spiral, repeating the squiggly dot at the each successive prime number. As a finishing touch – and as a last-second decision – I ended the quilting with the infinity symbol. The back features a novelty print with math equations and chemistry and physics diagrams. I usually don’t require anything more than a page or two of scratch paper to design a quilt. This time though, since maths were involved, I started off using InDesign to figure out the quilt pattern, but in an ultimate nod to geekery in quilting, I ultimately used colored cells in Excel to more accurately count the number of prints and solids I needed to cut.

Do you see the spiral? Here’s a diagram to get you started…