Almost a year ago, I rounded up my meager collection of resins (in liquid form) and did a sniffing of each. I still find their strong personalities challenging to work with, except for elemi, which is refreshingly friendly. I’ve since bought a few more—here they are.

Agarwood (Aquilaria agallocha Roxb.)

Also known as aloeswood or eaglewood, the legendary perfumery material oud has many facets, including a humble appearance as a dark brown paste in my little vial of SCO2 extract, which was sourced from “India commercial cultivation” per the label. Apparently A. malaccensis and A. crassna are the best-known species that produce agarwood, but A. agallocha Roxb. may be a legit “entry-level oud.” Having no comparators (except a synthetic blend by Firmenich called Pretty Oud, which lives up fully to its name), I feel underqualified to join the vast discussion about oud, but I can share some impressions.

It’s unpredictable. The only constant is a sour element, but what greets my nose from the vial or a scent strip (with a 10% dilution in isopropyl myristate) varies. Sometimes it’s like damp wood and rotting plant matter. Or an unwashed dog possibly splattered in its own excrement. Perhaps a very overripe fruit. Past those “pongs” of pungent aromas, and as the blotter dries, the scent becomes calmer, smoother, richer, deeper. It has some sweet smoke nuances, and the fragrance makes me think of an old wood—I imagine gnarly, in a venerable way. A naturally refined thing of beauty.

As for the synthetic Pretty Oud, it’s leathery and cold-smoky with a hint of cherry syrup in the fumes. An initial pairing with cassis (blackcurrant) base smells highly promising.

Copaiba balsam (Copaifera officinalis)

This is an oleoresin with hints of gentle wood. Its aroma is very mild and slightly mentholated, as typical of terpenic compounds. A vague sweetness recalls a watery, white-fleshed, soft fruit (dragonfruit, maybe?) I perceive a pasty quality that makes me think of powder dissolved in clear oil, or maybe the consistency of SweeTARTS candy melting in the mouth. It wasn’t surprising for me to learn that copaiba balsam is used as a fixative in natural perfumery.

Mastic (Pistacia lentiscus)

Sometimes called lentisque, this resin is used to make chewing gum in some regions. Mastic is one of the few perfumery materials I thought I could recognize in perfumes without having smelled the ingredient on its own before, because Kastellorizo by Maison de Parfum Berry made such an impression with its chalky, gummy quality that I thought the note couldn’t hide. I’ve since been surprised by learning of its presence in other perfumes such as Annick Goutal Ninfeo Mio; not so surprised that it’s in Tom Ford Costa Azzurra with its connotations of salty seascape and associated architecture.

Now that I have the real thing in front of me—the essential oil, that is—could it be a cousin of galbanum?! Turns out it isn’t, but they share a bitter greenness, which soon becomes minty and herbal. It’s also citrusy with a backdrop of fresh woodiness that would probably complement elemi or frankincense (olibanum) quite well.

Each vial holds its own miniature world.