The 1892 definitive issues of Argentina include two distinct colors of the 1/2 centavo stamp. A dull or gray blue that's quite common and a much more intense ultramarine that's also much harder to find. Guillermo Jalil's 2002 catalog list both colors in the default perf 11 1/2, but not in the less common perf 12 1/4 or the compound perf. I can't find my Kneitchel but when I put my pages together initially I left the ultra out for the two perf varieties. I now have an example sitting here that it the bright ultra and perf 12 1/4. Is it a new find or did Guillermo just leave it out by accident? I don't have his new catalog so can't check to see if it's been added, and he's usually very good at listing everything.