The International Playing-Card Society holds Conventions annually in the Autumn, the venue usually being located in Europe or America. The last Conventions were held at Toronto (Canada) in 2009, at Lisbon (Portugal) in 2010, at Malmö (Sweden) in 2011, at Paris (France) in 2012, at La Tour-de-Peilz (Switzerland) in 2013, at Berlin (Germany) in 2014, at Turnhout (Belgium) in 2015, at Prague (Czech Republic) in 2016.
The page gives a lot of information ...
Museums with playing cards
Playing Card Societies
Links to Web pages of playing card researchers
.. and more
MikeH added at another thread:
Most ICPS articles, except for recent ones (i.e. the last couple of years), are on the Web. You just have to "Ask Alexander".
Of course you have to know what to ask. But it's pretty accommodating. You just type in a name or subject, or whatever. I've even asked for vol. number and number number. It brings up a mess of pages, and you click on one that looks promising.