Which technique is used to create shading and tones by using closely placed lines?

The technique that is primarily used to create shading and tones through closely placed lines is hatching. Hatching involves drawing parallel lines that can vary in density and spacing, allowing artists to suggest light and shadow in their artwork. By adjusting the distance between these lines, artists can create different values and a sense of depth, making the illusion of three-dimensionality in their drawings.

While cross-hatching also involves creating tones through lines, it specifically utilizes a crisscross pattern of lines layered over hatching to enhance the effect of shading. Scribbling generally refers to spontaneous, chaotic lines and does not provide deliberate shading in the same structured way. Blending, on the other hand, encompasses smudging or merging colors or tones, which is a different technique altogether. Thus, hatching is the correct answer as it most accurately describes the method of closely placed parallel lines used for shading.