Poland
The stamp exists also with the watermark "Posthorn Type 2 Multiple [Rev, SL] - III-6"
| Country: | Poland |
| Type: | Postage stamps |
| Series: | 300th anniv. of Polish newspaper Merkuriusz |
| Nominal: | 2.50 zł |
| Year: | 1961 |
| Perforation: | comb 11¾ x 12 |
| Mintage: | 300,000 |
300th anniv. of Polish newspaper Merkuriusz
 Front page of "Merkuriusz" |  "Proletaryat" first issue 1883 |  "Rzeczpospolita" first issue 1944 |