Thanks again to the generosity of Cymbaline, I have been trying a sample of Tonka Imperiale on and off for a few weeks now. When I first spray it on, I am immediately reminded of Spiriteuse Double Vanille, without the booze and less smoky. My sample of SDV does not last on my skin. I don't know why, but thankfully Tonka Imperiale has more presence for me.
I'm no expert, but if I'm correct, Guerlain has historically used vanilla and tonka a lot in their perfumes, being essential components of their famous Guerlinade. Jean-Paul Guerlain is quoted in Michael Edward's book on French Feminine Perfumes, saying something along the lines that in his opinion there are very few really great perfumes that don't contain some vanilla. I guess that is subjective; I can think of quite a few incredible perfumes that don't have vanilla in them, but I digress.
What I like about Tonka Imperiale is that it smells smooth and sophisticated. It's opening is gloriously thick and vanilla-ry, suffused with a touch of smoke, and there is a hint of almond in there as well. It wears quite light though once the top notes fade, in the sense that it is perhaps a bit more transparent than SDV, but more interesting, if that can make sense. Once the base is reached, the amber and tobacco notes do show through, always interlaced with the tonka/vanilla accord, but it is by no means a forceful fragrance. Wearing it, I feel comforted, yet suave at the same time. I'd venture that Tonka Imperiale is on the linear side, but it is high-class, top-quality stuff from start to finish. So far it is by far my favourite in the L'art et la Matiere line.
According to Fragrantica, Tonka Imperiale contains notes of tonka, rosemary, spices, white honey, vanilla, almond, woody notes, amber and tobacco.