The postage stamps of the old German state of Württemberg from the early 20th century are a captivating piece of philatelic history. Particularly noteworthy are the stamps issued in 1920 during the period of the Free People's State of Württemberg (Volksstaat Württemberg). This era was marked by significant political change following the end of World War I, as the monarchy was dissolved and Württemberg transitioned into a republic within the Weimar Republic.

Among the most valued issues from this period are the 20 Pfennig blue, 30 Pfennig mint green, 75 Pfennig light brown, 1.25 Mark lilac, and the 2.50 Mark blue stamps. These were released with the distinctive overprint “Staatsmarke,” which means “State Stamp,” emphasizing their official status within the new governmental framework.

### 20 Pfennig Blue and 30 Pfennig Mint Green
The 20 Pfennig blue and 30 Pfennig mint green stamps are sought after by collectors for their striking colors and historical significance. The 20 Pfennig, rendered in a vivid blue, and the 30 Pfennig, in a subtle mint green, reflect the practical postal rates of the era. Their crisp designs capture the transitional nature of Württemberg’s postal system as it adapted to new political realities.

### 75 Pfennig Light Brown
The 75 Pfennig light brown is rarer and holds great value due to its unique shade and limited issuance. The earthy tone of this stamp embodies the frugality and the cautious optimism of the post-war period. It was primarily used for higher postal rates and thus saw more limited circulation compared to lower denominations, enhancing its appeal to philatelists.

### 1.25 Mark Lilac and 2.50 Mark Blue
The higher denomination stamps, the 1.25 Mark lilac and 2.50 Mark blue, were issued for more expensive postal services. The 1.25 Mark in a regal lilac hue is a testament to the period’s efforts to retain a sense of dignity and resilience despite economic difficulties. Meanwhile, the 2.50 Mark blue, known for its rich color and bold overprint, represents the highest denomination of the series and is particularly valued for its scarcity in mint condition.

### Significance and Value
What makes these stamps exceptionally valuable is their “postfris” (mint, unused) condition. Collectors prize mint-condition stamps for their impeccable preservation, which ensures that their colors and print details remain as vivid as when they were first issued. The “Staatsmarke” overprint further distinguishes these stamps, symbolizing their issuance under the authority of the newly established republican state.

These stamps not only hold monetary value but also embody a significant chapter in the history of Württemberg. They are tangible reminders of the period's cultural and political transitions, cherished by historians and philatelists alike for their aesthetic and historical resonance.