Seltmann Weiden is a renowned German porcelain manufacturer founded in 1901 by Wilhelm Seltmann in Weiden, Bavaria. The company quickly established a reputation for producing high-quality porcelain dinnerware and decorative items, often featuring classic designs and intricate patterns. Their "Royal China" line signifies a particular standard of quality and aesthetic appeal, often associated with elegant tableware. Мark, combined with the "Royal China" designation, suggests a piece from the 1970s or 1980s.