The term "Nistari" refers to a particular variety of silk yarn produced through traditional reeling techniques practiced by local artisan communities. The yarn is produced from mulberry silk (Bombyx mori), one of the finest and most widely used silk varieties in the world. The process begins with sericulture, where mulberry plants are cultivated and their leaves are used to feed silkworms.

In Bengal, sericulture is typically practiced during several cycles through the year, with major rearing seasons occurring between March–April, June–July, and September–October, depending on climatic conditions and mulberry leaf availability.

Once the silkworms spin their cocoons, the cocoons are harvested and subjected to controlled boiling or steaming, which softens the natural sericin binding the silk filaments. The silk filaments are then carefully reeled from multiple cocoons simultaneously to form continuous threads, a process requiring precise control of temperature, water quality and filament tension.

The extremely fine filaments are subsequently combined and twisted to produce strong and uniform silk yarn, valued for its smooth texture, natural lustre and tensile strength.

Historically, Malda's silk yarn production has been closely linked with the weaving traditions of Bengal, supplying raw silk to nearby weaving centres. These yarns are later used by handloom weavers to create traditional silk textiles such as Garad, Korial and other silk fabrics woven across Bengal's historic weaving regions.