Which hair cutting technique adds layers while maintaining length?

The technique that adds layers while maintaining length is known as slide cutting. This method involves using the cutting edge of the scissors to slide down the hair shaft while cutting, which removes weight and creates more movement and softness in the hair without drastically altering its overall length. Slide cutting is particularly effective for creating layers that blend well with the existing lengths, providing a more textured and natural appearance.

Thinning, for instance, typically reduces the bulk of the hair and is more focused on volume rather than creating structured layers. Point cutting is a method usually employed to texturize or soften ends, primarily altering the finish of the cut rather than layering the hair. Blunt cutting results in a straight edge with no layers, creating a more solid look, which contrasts with the layered effect of slide cutting. Thus, slide cutting distinctly serves the purpose of layering while keeping the length intact, making it the most suitable choice for this question.