 Prominent Finnish designers include Alvar Aalto (vases, furniture), Aino Aalto (glassware), Kaj Franck (glass, tableware), Klaus Haapaniemi (fabric prints), Simo Heikkilä (furniture), Kristina Isola (textiles), Maija Isola (Marimekko prints), Harri Koskinen (glass, homeware), Mika Piirainen (clothing, accessories), Timo Sarpaneva (glass, homeware), Oiva Toikka (glass art), Tapio Wirkkala (glass art, glassware), Eero Aarnio (plastic furniture), Sanna Annukka (screenprints), Anu Penttinen (glass), Aino-Maija Metsola (textiles, homeware), and Maija Louekari (tableware, homeware).Design in Iceland is a relatively young tradition, starting in the 1950s but now growing rapidly.The country's limited options for manufacturing and its constrained choice of materials have both forced designers to be innovative, though wool remains a staple material, whether felted or knitted.