Kate and Dick Jones, founders of Kadon Enterprises, Inc., were invited and attended, bringing along some special anniversary puzzles. A limited edition of Kadon's logo puzzle was engraved on the front with the Kadon inscription, and on the back, around the big "25," it honored the IPP's milestone. Here's a view of both sides. Oh, yes, the "25" cut-out is one of the solvable figures — fill it with all 25 puzzle pieces.

Kate had entered one of her designs in the IPP's annual puzzle design competition. While it did not win a prize, it did engage many of the puzzlers in solving attempts. The 25-tile Arc Angles in black and silver was available only during the anniversary year. After 2005 it took on new life in a more colorful form. The anniversary set looked like this when 5 groups of 5 arc-shaped tiles formed rings:

Besides days of puzzle exchanging, presentations, design competitions and sightseeing, one day was set aside for the official "puzzle party" with exhibitions and selling. The large exhibit hall teemed with enthusiastic collectors searching for treasures. Looks a lot like a comic book, gaming, or sci-fi convention or computer trade show, doesn't it? The average IQ in the room was close to double that of body temperature.

This annual gathering is truly the world's "Who Is Who" of puzzledom, both creators and collectors. And to think all this started a quarter century ago as an intimate gathering of a few puzzle-loving friends in Jerry Slocum's living room!

Down on the sales floor, Kate's very condensed display offered Kadon's unique brand of put-together puzzles — artistic, challenging, beautiful. Kate had brought along some of her hardest puzzles for this crowd.



It was also a great time for meeting up with old friends and fellow designers. Here's Kate with, from top to bottom, Bill Ritchie, president of ThinkFun, Inc. (formerly Binary Arts); Dr. Andy Liu, professor of mathematics at the University of Alberta; and Sjaak Griffioen, inventor of Kadon's Leaves puzzle.

A one-day excursion around the city of Helsinki and its glorious harbor included a stop at the Heureka science museum, a fine example of the Finns' brilliant sense of design. The main plaza was paved with a Penrose tiling of kites and darts, showing their non-periodic character.

Another famous tourist attraction is Helsinki's Rock Church, built entirely underground by digging out a hill, with only a dome showing through. A circle of sturdy old buildings, housing apartments and shops, surrounds it like a fairytale city.

Photo credits:
Kate and Andy and the Penrose tiling at Heureka by Jane Nash.
Rock Church from a tourist postcard sold in the church's giftshop.
All other photos by Dick Jones. See a large collection of
other photos of the Puzzle Party by Jane Nash.