Issued on April 15, 1927, Luxembourg’s first postal viewcards have not been much studied. Thus, their nine Mondorf-les-Bains views provide a fertile field for philatelic research.
Consider, for example, the 30c fountain view. I’ve found three variations in the spacing between the stamp imprint and the four adjacent lines of text:
No space between the stamp imprint and text.
1 mm. of space between the stamp imprint and text.
Check your postal stationery collection. Help me identify more of the varieties on these distinctive postal viewcards!