Scraping Heuk Pi  (black layer)
This process is very labor intensive but necessary in order to obtain the finest Baek Pi (white layer). Dak bark consists of three layers: black outer layer, green middle layer, and white inner layer. Dried Dak bark is first soaked in running water overnight prior to scraping. Part of the black layer is deskinned by treading on the bark. Then each bark is scraped using a knife until only the white layer is obtained. Scar tissue or any impurites are also removed. Cleaness of a final sheet depends largely on how carefully Baek Pi is prepared at this stage. Through this process, only 30-50% of original material is retrieved. Small percentage of yield paired with intensive labor is what affects the quality and price of a sheet.

With rising labor costs and unavailability of farmers willing to lend their hands for such hard work during winter time, increasing number of contemporary papermakers reserve Baek Pi for only the finest quality Hanji. For common grade paper, bleached Heuk Pi (black layer) is widely used to lower the material cost. In this case, scraping process is bypassed and Heuk Pi is ready for cooking.

FIDES 1000 and 5000 series Hanji are made from 100% Baek Dak.

Cooking Dak in alkali
Dry Dak bark is soaked in running water overnight. This helps dissolve water soluble impurities and softens the bark, making it easier to cook.

Cleaned Baek Pi or Heuk Pi is cooked in alkali solution to remove the non-cellulosics from the fiber. Traditionally, natural ash was obtained from rice straw, stalk of buckwheat, cotton plant, soy bean, or pepper. This is called Yuk Je. According to old documents, mugwort stalk was considered to be the best material for alkali. However, it takes enormous amount of time and energy to maintain this tradition, which is why many contemporary papermakers often work with soda ash or caustic soda. Natural plant ash is considered to be the mildest alkali for fiber, followed by soda ash and caustic soda. Cooking time varies by the type of alkali, but fiber is cooked until soft.

FIDES 5600 Series fibers are cooked with buckwheat ash.

Rinsing
Cooked Dak fiber is rinsed in clean running water. It is kept in water long enough for alkali residue or other impurities to wash away.

Baek Pi (white layer) is naturally bleached in water from the sun. In regions with high snow precipitation, fiber is bleached on clean snow.

Removal of scar tissue on Dak fiber
As the last step in the cleaning stage, any impurities, buds or scar tissues are removed from the fiber once again by hand. All specks must be removed in order to attain a clean paper surface. For projects requiring clean surface, extended care and time is given to prepare the fiber.

Go Hae  (Beating the fiber)
Dak fiber is completely separated by beating. Traditionally, the fiber for Hanji was beaten by hand on a stone or wood panel. Many papermakers now rely on automated equipments to separate the fiber.