| Added by |
 Maciej Pasztor
|
| Face value | 6 mark |
| Catalog code (Michel) | Porto 40 |
| Catalog code (Scott) | POSTAGE DUE J43 |
| Catalog code | Polish Stamps Catalog D40 (Znaczki dopłaty) |
| Series | Numbers and Eagle |
| Place in series | 4 |
| Stamp colour | Indigo |
| Stamp use | Postage Due stamp |
| Print run | 3,282,000 |
| Issue date | 15/04/1921 |
| Designer | Edward Trojanowski |
| Paper type | gray laid (horizontally or vertically) |
| Print technique | Typography |
| Printed by | PZG Warszawa |
| Perforation | 9 - 14½ (line) |
| Height | 21.50 mm |
| Width | 17.00 mm |
| Catalog prices | No catalog prices set yet |
