NO FIRM IN history has had as penetrating an impact on everyday design and taste as IKEA. Even if you have never found yourself winding through a shop, absent-mindedly adding “Billy” bookcases, “Rodalm” picture frames or “Glimma” tea lights to a trolley, you will probably have encountered “Stockholm” rugs, “Rinnig” tea towels or “Ektorp” sofas in the homes of friends or in Airbnbs. This is, after all, a company with over 480 shops in 63 countries, which generated around €45bn ($52bn) in sales last year.