Back near the end of the summer, I got a lot of sewing done. Specifically, I made a lot of progress using up fabric that I already owned, and I made six quilt tops (two queen size and four crib size). Today, in preparation for the upcoming termite tenting in my building and all its weird rules about things that contain air wrapped in plastic – such as an unopened queen size quilt batt – I brought three more quilt tops to the long-arm quilting shop to be professionally quilted, including one of the queen size quilts.

Grey and brown quilt top

The major design theme of this quilt was “use up fabric that you already own.” About a quarter of the squares were the same grey linen that I’ve also been using to make my ridiculous shopping bags.

I happen to have owned a lot of grey and brown and green fabrics, so I cut them up into 6-inch squares (finished sized). Once there weren’t any pieces left that were big enough to make 6-inch squares, I cut the rest of the scraps into 3-inch and 2-inch and 1.5-inch squares. And once I had enough squares and sub-squares, I sewed all the sub-squares together into 6-inch squares. Next, I sewed my squares together into 14 strips that were each 14 squares long. Finally, I sewed those 14 strips together into the quilt top.

The tricky part happened once I reached the last stage. Earlier on I had just sort of assumed that I did not want to have any identical squares next to each other. When I was working with the small squares, this was easy. When I was sewing the 6-inch squares together into the 1-by-14 strips, this was also easy: It was easy to tell if I was about to sew two identical squares to each other and then just rotate a sub-strip by 180 degrees (pi radians, for you purists) or do some other easy swap.

However, once I reached the point where I had 14 strips, it was a lot harder to tell if any given pair would have identical squares touching if you sewed their long sides together. (I live in a small apartment, and the strips were each seven feet long.) Even worse, if a given pair were incompatible and I switched one out at random, would I just end up having identical squares touch later in the process with no way out?

My solution to this problem was to give up early and make sure that I had more than one pair of identical squares touching – so that it would look like it might be intentional. But now I am thinking of writing a combinatorics problem where if you know the number of squares of each color (and the size of the quilt), you would find the probability that you could assemble all the strips without identical patches touching each other.