Ari Korolainen is a Finnish architect and designer who was one of the first designers who used recycled materials in his designs. 1985 he started to make cases and stationery products of recycled cardboard. Today he also uses recycled leather commonly in his designs. Good design and environmentally friendly materials can be seen in his Private Case stationery collection. Now, 30 years later, Private Case is a large collection of stationery products and Korolainen is known as Mr Private Case. Furniture design is his another ambition.