The internationally significant collection focuses on glass and ceramics and features Finnish design from modernism to the present day. Collection Kakkonen focuses on the post-war era, i.e. the so-called golden age of design. During this time, Finnish design also gained more ground internationally. The core of Collection Kakkonen includes unique design, art glass and ceramics and their makers. The collection consists of works from over 30 artists and a total of 10,000 objects.

Central names included in the collection are e.g. Alvar Aalto, Rut Bryk, Kaj Franck, Birger Kaipiainen, Toini Muona, Gunnel Nyman, Kristina Riska, Kyllikki Salmenhaara, Markku Salo, Timo Sarpaneva, Michael Schilkin, Kim Simonsson, Nanny Still, Oiva Toikka, Kati Tuominen-Niittylä, Helena Tynell, Vesa Varrela and Tapio Wirkkala.