Feature Guide
A small number or letter stamped on the back of vintage Levis front buttons identifies the manufacturing facility. This factory code appears on models from roughly the 1950s through 2002. Three main stamp types exist. Single-digit stamp = pre-mid-1970s domestic factory. 3-digit stamp (factory code) = late American-made, 1980s–2002. Letter stamp (M, W, etc.) = overseas factory. The stamp type itself serves as a supplementary dating indicator.
Dating by stamp type: single-digit = pre-mid-1970s, mostly major US domestic factories (numbers 1–6 etc.). Underlined '6' = characteristic of 1970s. 3-digit stamp (e.g. 230, 453) = common in late American-made pieces, 1980s–2002. Letter stamp (M, W, E, etc.) = overseas factory (Mexico, Europe, etc.), common post-1990s. No stamp (unstamped) = very early piece or worn beyond reading. Combining these with red tab and care label simultaneously narrows era and country of origin.
Levi Strauss emigrated to San Francisco in 1853 and established the world's first jeans factory on Valencia Street in 1873 — the very birthplace of Levis. Button stamps 1 (Valencia Street factory) and 2 (22nd Street factory) identify pieces made at this historic origin point. These SF factories closed as American denim manufacturing declined. The combination of historical significance as the brand's birthplace and limited surviving quantities gives SF factory Levis their special rarity — SF factory provenance can affect valuation even between same-era, same-condition pieces.
Major factory numbers (single-digit): 1 = Valencia Street Factory (San Francisco, CA) — Levis birthplace, rarest. 2 = 22nd Street Factory (San Francisco, CA) — SF second factory, rarest. 3 = Sioux City Factory (Iowa) — moderate rarity. 4 = Amarillo Factory (Texas) — standard rarity. 5 = Blackstone Factory (Virginia) — standard rarity. 6 = El Paso Factory (Texas) — standard rarity. Factory number interpretations vary among researchers, and the same number may have corresponded to different facilities at different times. Always combine with other dating points for comprehensive assessment.
Button back stamps are small and often worn — correct photography technique is critical. Pull the button from the waistband to expose the back. Hold a phone light at roughly 45 degrees to the stamp (angled light makes the relief stand out). Use macro mode to shoot close-up, ensuring the number is legible in the frame. For faint stamps, try multiple angles and use the sharpest result. Checking all front buttons (usually five) increases certainty — confirming the same number on multiple buttons improves reliability. 3-digit stamps are relatively readable; single-digit stamps are often worn and especially benefit from angled lighting.
Upload photos and AI instantly identifies era, model & factory
Identify for FreeRelated Articles
Feature Guide
Complete Red Tab Guide — Big E, Small e, Trademark R & Tab Orientation
Feature Guide
Complete Zipper Brand Dating Guide — Scovill, Conmar, TALON, YKK
Feature Guide
Complete Care Label Dating Guide — Narrowing to a Decade
Feature Guide
Complete Selvedge & Outseam Guide — Overlock Color Dating 1981–1993