What printing techniques is especially capable of producing subtle shades of gray?

The printing technique especially capable of producing subtle shades of gray is photogravure. This method utilizes a photographic process to create a continuous tone image, allowing for smooth gradations and a wide range of gray tones. Additionally, giclee printing, which employs inkjet technology, can also achieve fine tonal variations and detailed gradients, making it suitable for high-quality reproductions of photographs and artworks.