Practice Suturing techniques are used in medical procedures such as surgery to close wounds. It is important to learn how to do it safely and correctly. Surgical thread and needles come in many shapes and sizes. Round needles, curved needles, cutting needles, needles with a large eye at the tip for heavy materials. Such as bone, small-eyed needles for fine suturing jobs such as those done on babies’ eyes during an operation for cataracts.