Hiroshi Yoshida was a leading figure in the shin hanga (new print) movement. He worked primarily as a painter until his late forties when he became fascinated with woodblock printing. After working with the Watanabe print shop for several years, Yoshida decided to fund his own workshop. Unlike ukiyo-e artists, he was intimately involved in all parts of the printmaking process. He designed the key blocks, chose the colours for the prints, and supervised the printers. In some cases, he even helped to carve the printing blocks. This was unusual, considering the traditional division of labour between designer, carver, and printer at that time. The majority of Yoshida's prints are richly detailed landscapes, featuring such diverse subjects as the Sphinx, the Taj Mahal and Mount Rainier. Yoshida travelled frequently and made sketching and painting trips all around the world. He was an avid mountain climber, and is noted for his depiction of alpine scenes. He also was remarkably skilled at depicting water, with its intricate reflections and complex flow patterns. Yoshida's prints were very popular with Western collectors, and he was one of the only shin hanga artists to sign and title his prints in English. The most important mark on a Hiroshi Yoshida print is the jizuri seal. Jizuri can be translated as "printed by myself" or "self-printed". Unlike many of his contemporaries, Yoshida did not utilize a publisher to print his works (with the exception of several prints published by Watanabe Shozaburo prior to 1923). Instead Yoshida worked with printers in his own studio, mixing his own colours and closely supervising the printing process. Only original prints of the highest quality were marked with the jizuri seal. Yoshida's older son, Toshi Yoshida, supervised much of the printing during the late 1930's and 1940's, when his father was busy on other projects
The jizuri seal is usually found in the left-hand margin of the print, above the Japanese title and date characters. On a few prints, it is stamped in the right margin or bottom margin. In addition to the jizuri seal, original prints have a Japanese signature written in sumi ink within the image. Since many of Yoshida's prints were sold to Westerners, he often signed his prints in pencil in the bottom margin. When original Yoshida prints lack a pencil signature, it means that they were most likely intended for the Japanese market. It does not detract from their value. Many of Yoshida's works were reprinted in the years following his death in 1950. These posthumous prints do not have the jizuri seal, and are usually of lesser quality than original prints. They bear a stamped signature and title in the bottom margin, which looks suspiciously like pencil until examined closely. The value of these restrikes is considerably less than that of original Yoshida prints. The jizuri seal on original Hiroshi Yoshida prints is usually stamped in brown or black ink. However, a few of Yoshida's earliest designs were stamped with a bright red jizuri seal. Hiroshi Yoshida prints with red jizuri seals often vary in colour from the "normal" dark jizuri versions. The red jizuri prints have dramatic bright colours while the brown jizuri prints are typically more realistic and toned down. Yoshida prints with a red jizuri seal are rare, and some people have theorized that these prints were originally intended for the Japanese market. Japanese collectors did tend to prefer more brightly coloured prints. In some cases but certainly not all, red jizuri prints lack English signatures and titles. However, there were also brown jizuri prints sold in Japan that lack an English title and signature. So it is unlikely that the red jizuri indicated a "special" version for Japanese customers. More likely, the red jizuri seal is simply an indication of a variant colour choice. Red jizuri seals are primarily found on early Yoshida prints from the North America series, Europe series, and Japanese Alps series. In 1925, Yoshida started his own woodblock studio and he devoted much of his time to printmaking. He published over 50 prints during 1925 and 1926, including many of his finest designs. Yoshida had more time and perhaps more desire to experiment with colours on his early prints.