In the early 19th century, schoolgirls in Northern Europe made darning samplers to learn the crucial skill of mending, practicing a range of embroidery and darning techniques that could extend the life of garments and household textiles. Although these repairs have a beauty all their own when made in contrasting thread, they were ultimately intended to be invisible. The use of two-colored threads allowed students to discern the underlying weave structure; students would gradually transition to using one color of thread as they gained skill.