If you are not an avid collector of vintage Lanvin perfume extraits that come in rectangle bottles, here is my unofficial guide: Extraits with silver labels and all black stoppers are the oldest (~1940s, fig.1), then comes gold labels and twist caps with gold collars (~1950s-1960s, fig. 2), and occasionally blue labels and black plastic screw caps (~1960s, for small sizes, fig. 3) and finally black labels, gold lettering and twist caps with gold collars (1970s-80s, fig. 4). Assuming the formula and the quality of the materials used have never changed, I suggest getting the ones with black labels (only apply to Arpège, My Sin and Remuer) because they smell freshest.
Created by Andre Fraysse, Lanvin Prétexte debut in 1937, had a good running of 25 years, and was discontinued in 1963. I have two versions of Prétexte extraits, one that comes in a 1oz bottle with a silver label (1940s) and little samples with gold labels that indicates they are from the 1960s. The 1oz bottle is much more valuable and hard to get, but the little samples smell much better.
Pretext is a stunning, resinous, powdery, floral chypre with a strong animalic, soft leathery base. The opening has an unmistakable aldehyde note, immediately follows by two distinct scent accords of equal strength: 1) creamy soft white florals (narcissus, iris) and sandalwood and sweet tonka, and 2) a rich chypre base (patchouli, oak moss) with leather, civet, woodnotes. As the scent develops, interestingly part 1) wins and becomes a soft sandalwood floral perfume. I’d dare to say overall Prétexte smells richer and creamier than Arpège, but it doesn’t have the signature abstract floral uniqueness that Arpège possesses.