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Step 1: Photography and Retouching
The original manga artwork is photographed using Phase One Cultural Heritage. Then, detailed color adjustments and retouching are performed on a computer. While looking at the colors used in the artwork and the detailed touches, we think about exactly what colors to print with and the order in which to print them. We then decide on the overall design and process.
In the standard printing process, hues and shading are produced by mixing dots of the four CMYK colors. To create an artwork using the collotype printing process, however, we must create our own special colors for the work, which are then layered much like the process for creating a woodblock print, and then printed. For BLEACH: The Millennium, eight colors were used. We decided to divide the data into eight "plates."
When producing a color plate, such as a skin tone plate, if the black sections are cut out completely, it will result in a depthless, unnatural tonal expression. For this reason, black sections were selected and blended in with the surrounding colors during this process. This allows for a rich tonal expression that reproduces the texture of an actual hand drawing.
A Mac and a drawing tablet were used for this process. Each color is adjusted with texture and three-dimensionality in mind, in addition to the color tones themselves.
Printing vibrant manga illustrations that were originally drawn on highly whitened paper using colorful dye-based markers was an extremely difficult challenge even for the Benrido collotype studio, founded in 1905. Some content, like orange hair and translucent skin, was especially challenging to produce. Tests were repeatedly conducted in order to create these colors on washi paper, which has a natural, unbleached base color.
Step 2: Color Dodge on Film
The separated color data produced in Step 1 was output onto negative film using Kodak's Flexcel NX. The output film was then checked to see if it is suitable. For areas where less exposure is desired, retouching work was performed directly on the negative with a Stabilo all-graphite pencil.
Then, the negative film was overlaid on the glass plate for exposure. It takes skill and experience to assess the transmission of light from the negative. If the exposure time is too short, the image will not appear on the plate, and if it is too long, the gradations may distort, resulting in an unsuitable print.
At first glance, color expression in manga appears simple. However, a single illustration can feature both edgy color expression and delicate, smooth shading, and the simplicity of the image makes color smudges and gaps particularly stand out. The art should be both bold and subtle. Achieving both qualities through plate making was an extremely difficult task.
Step 3: Producing Printing Plates
Glass plates are used for collotype printing. The dimensions are 1,250 mm by 700 mm, with a thickness of 10 mm. Gelatin with photosensitizing solution is poured at this stage to create the plate.
The "collo" in the word collotype refers to gelatinous glue, or gelatin. Gelatin containing photosensitive liquid hardens when exposed to light, and it is this property of the gelatin that is utilized in this process.
First, gelatin mixed with photosensitive solution is made and cooled in a dark room. The solution is left overnight. The following day, gelatin is poured on a prepared glass surface. Gelatin containing photosensitizing solution is viscous and tends to harden and cause irregularities. For this reason, two people work together to apply the gelatin evenly. Dust and air bubbles are removed with a dropper. The glass is then lifted and tilted from side to side. By doing so, the thickness of the gelatin plate can be made evened.
Dust and air bubbles are removed again, and the gelatin plates are placed horizontally in a dryer. The plates are heated to 55 degrees Celsius for 45 minutes. They are further preheated to dry for another 45 minutes. The drying process is complete when the temperature returns to room temperature, and the product is stored in a dark box in preparation for the exposure process.
Gelatin is a volatile material. Its condition changes from day to day, and thorough temperature and humidity control is required to keep it stable.
Step 4: Exposure on Gelatin Plates
The film negative made in Step 2 is adhered to the printing plate made in Step 3 and is exposed using ultraviolet light. In this process, the image on the negative film is transferred onto the gelatin plate.
Two people check the placement and decide on the exposure position based on the trim marks on the negative film. A mat is laid down, and vacuum contact is performed to ensure that the image forms properly. After the exposure process, the glass plate is placed in water. The photosensitizing solution is rinsed off to prevent further exposure. The plate is then dried after rinsing. It is once again stored in a dark box until the printing process the following day.
Step 5: Printing
Now it is finally time to print the artwork. The video shows the seventh color, blue, in the process of being printed.
The gelatin plate is immersed in a water and glycerin solution, then set into the machine. After adjusting the plate again with glycerin solution, etc., printing takes place using specially blended ink.
For this printing, the studio's largest collotype press is used. It was made by Hirose Iron Works Co., Ltd in Osaka in July 1994. Gelatin plates with dimensions of up to 1,250 mm by 700 mm can be loaded into this machine. The pressure generated at the time of printing exceeds one ton. The ink was specially adjusted by Mitsuboshi Printing Ink Co., a company based in Sakai, Osaka. With a high pigment concentration averaging 60%, this ink is extremely weather resistant and durable.
The gelatin plate produced in Step 4 is immersed in water again at the printing station to expand the gelatin. This process causes the gelatin to develop microscopic creases called reticulations. The level of shading produced depends on the amount of ink that penetrates these creases. (Note 1)
Once the gelatin plate is prepared, the ink is placed on top of it, and test prints are conducted repeatedly until a suitable result is achieved. The ink is a mixture of colors selected from about 40 different hues. Due to the hard, viscous nature of the ink, it is difficult for the machine to dispense ink automatically. Therefore, the craftsmen use spatulas to feed ink directly onto the printing press.
The paper is passed through the printing press twice to print one color. This process must be done in order to bring out the rich gradations that make collotype printing unique, as it is preferable to print the paper twice lightly rather than create one dense print. The colors are layered in a similar fashion to ukiyo-e printing to produce color tones, texture, and three-dimensionality. By being aware of the base color of the paper and producing shading by adjusting the amount of ink as they go, the craftsmen are able to carry out the printing process in a steady manner.
The process requires refined senses and technical skill.
Note 1: Collotype is a lithographic printing method that utilizes the relationship between water and oil, but it is also similar to intaglio printing in terms of the way the reticulations (creases) are used. The white part of the negative (the shadow areas) allows light to pass through easily, so the gelatin plate hardens during exposure, and the ink adheres to it because it does not contain water. The process also creates deep recesses for reticulation, allowing more ink to enter. The black areas of the negatives (the highlights) do not allow light to pass through, so the gelatin plates do not harden at these points. Since water is contained at these points, oil is repelled, thus preventing ink from adhering.
