The chemistry of longevity
The unusual durability of traditional Samarkand paper, which can last for 300 to 400 years compared to the 40-50 year lifespan of some modern papers, is directly linked to the chemistry of its primary water source, the Siab River. This waterway, which flows through the Konigil village where the paper is made, has a specific mineral composition that imparts preservative qualities to the final product. The important ingredients are dissolved compounds of calcium and magnesium. These minerals, particularly calcium carbonate, create an alkaline buffer within the paper fibers.
This alkaline reserve is chemically significant because it neutralizes acids. Paper degrades over time primarily through a process called acid hydrolysis, where acidic compounds break down the long cellulose fibers that give paper its structure. These acids can come from atmospheric pollutants or from lignin, a component of the raw material itself. By maintaining a neutral or slightly alkaline pH, typically between 7.5 and 9.5, the calcium carbonate from the Siab River water prevents this destructive process from starting. Modern archival papers often have 3% calcium carbonate added intentionally to create this same effect. In Samarkand, the water provides this naturally.
From mulberry to manuscript
The traditional production process, revived in 1995 at the Meros paper mill in Konigil, works with the water's properties. The raw material is the inner bark, or cambium, of young mulberry tree branches. After being harvested, the bark is cleaned and boiled for several hours in large vats of the mineral-rich river water. This prolonged boiling softens the fibers and helps infuse them with the water's alkaline minerals.
Following the boiling stage, the softened bark is pounded into a uniform pulp. Historically, this was done by hand, but the modern Meros mill uses a large water wheel, also powered by the Siab River, to mechanize the process. This pulp is then mixed with more water to create a slurry. A craftsman dips a fine sieve into the slurry, lifting a thin, even layer of fibers. After being pressed and dried vertically for a day, the sheet is complete. The final step, an innovation credited to Samarkand artisans, involves polishing the paper's surface. The sheet is placed on a smooth marble table and rubbed with an agate stone or large seashell, creating a glossy, non-porous surface ideal for calligraphy. This entire process, from branch to polished sheet, uses no chemical bleaching agents, which contributes to the paper's characteristic light ochre or yellowish tint and its remarkable longevity.