100 Rupees - Birendra Bir Bikram Shah

This note ran across an unusually long production window — twenty years and six distinguishable signature-and-security variants — making it one of the more systematically documented series in Nepalese paper money. The earliest issues carry a manufacturing anomaly: a faint line extending from the king's lip downward, an artifact of the De La Rue plate that was corrected mid-run, creating the first major collecting distinction within the series. Serial number placement migrated from the chest area of the portrait to a separate panel, and the security thread evolved from absent to windowed, with the final Shrestha-signed issues further subdivided by serial number length — 20 mm versus 24 mm — a difference measurable only with a ruler but catalogued as distinct varieties.

The 1990 signature transition to Tripathi coincides with Nepal's democratic revolution that year, which ended Birendra's absolute rule. The king retained his portrait on the note; the political system around it changed entirely.