Hatching and cross-hatching are artistic techniques in which artists use closely-spaced parallel or crossed lines to create tonal or shading effects in their work. By varying the length, angle, spacing, and thickness of these lines, artists achieve a variety of visual effects. Western artists developed cross-hatching in the Middle Ages, and many 15th-century old master prints contain examples of the technique. Which artist is said to have perfected the techniques in his woodcuts and engravings? Discuss