Cathedral Window is a traditional patchwork technique interpreted in old quilts as rows of folded squares of off-white or cream-colored muslin with assorted fabric squares in the Windows. It requires about four times its area in the folded squares, so a large amount of fabric is needed for the base of the quilt. Because of the four folds involved in each of the blocks, the resulting quilt also tends to be heavy and therefore does not require batting (or backing) or any quilting. Due to its delicate construction, it is often used more as a bedspread than as a quilt itself.
The traditional Cathedral Window unit consists of two folded squares of background fabric plus one smaller square of colored fabric for the window: