If you know this maker, you know that this pattern in particular is very sought after and is actually selling (not just listed) on eBay for about $30/plate (11.25 inches in diameter) or more and I have 8 of them that look like they have never been used (but I am sure they have).
They are Luxembourg Porcelain (as you can see on the label) and, surprisingly, are dishwasher safe! Since they are vintage (produced between 1984 - 98), I was surprised to see this.