The article below was originally published in the November 2007 issue of the HOACGA newsletter.
Bob wrote this article in 2007, naming the pattern Helsinki. He didn't realize that Glen and Steve Thistlewood had previously discovered a vase in the same pattern, with the moulded Riihimaki trademark on its base. They had given it the pattern name Kaaro, as they had also discovered the vase in a Riihimaki catalog with that OMN (original manufacturer's name) pattern name given to it. (Not all Riihimaki catalogs provide pattern names.) All of this was published in their The Art of Carnival Glass, published in 2004, page 24. Also see their Carnival Glass from Europe Encyclopedia e-book, page 142 for more information.
Below is an image from an original Riihimaki catalog showing several pieces in the pattern.