Think of the world’s greatest interior designers and then go just a little higher, into the stratosphere of chic, and you will find Jacques Grange. He is, in fact, more portraitist than designer: a seer of souls in the vein of Goya, Bacon or Picasso, conjuring rooms with his insight into the unexpressed yearnings of his clients. His brushstrokes, however, are so singular that to the untrained eye, it’s diffcult to pick two interiors as being by the same hand. One might be patterned and romantic, another is playful and yet another is streamlined and sleek. None allow for quick categorisation, united only in their spirit of elegant nonchalance, a predilection for all things Jean-Michel Frank and what seems to be a clientele in universal possession of exceptional paintings by…