Hadamard 160 in Cool Tones 2020 Embroidery floss, 14-count Aida cloth

This cross-stitch is of a 160 by 160 Hadamard matrix. Stitches represent 1s, the lack of a stitch represents a −1, and any two rows are orthogonal to each other. The matrix was constructed using Williamson matrices of order 40 that were found using MathCheck.