Anime follows the typical production of animation, including storyboarding, voice acting, character design, and cel production (Shirobako, itself a series, highlights many of the aspects involved in anime production). Since the 1990s, animators have increasingly used computer animation to improve the efficiency of the production process. Artists like Noburō Ōfuji pioneered the earliest anime works, which were experimental and consisted of images drawn on blackboards, stop motion animation of paper cutouts, and silhouette animation.