Sam Hecht, a designer at Industrial Facility, has created a new chair for Italian furniture manufacturer Mattiazzi. The Tronco chair, a stackable item aimed at churches. Hecht, who previously designed the Brancca chair, offers this description of the ash wood chair, launched at this month furniture show in Milan.   Tronco appears to be a very basic chair, its seat formed from planks of wood joined together and mounted on round dowels.