You all know the pain...Your otherwise beautiful opaque perfume bottle, often in inky shades of black or purple which spell danger or just in a material inpenetrable by the light (such as opaline, Cloisonné metal or china or reverse painted from inside glass, such as in Chinese snuff bottles), is refusing to let you gauge how much of the beautiful fragrance you so enjoy is left in it.
Consider some examples for a minute: Classics, like the architectural and oblong flacons in black glass for all the reissued Robert Piguet fragrances (Fracas, Bandit, Visa, Cravache, Baghari). The art-deco vintage bottle of Nuit de Noel by Caron with its beautiful 1920s "head band". The black boule of the original Arpège by Lanvin. The delicate, calligraphy-flowers-embossed original bottle of Shiseido's Zen. The cinnabar/orange-red of Opium parfum with its tassel.
Maybe modern or niche ones ones, such as Jasmin Noir by Bulgari. The square black of appropriately named Encre Noire by Lalique. The painted from inside glass bottles of Narciso Rodriguez Narciso For Her in the Eau de Toilette and the completely opaque black of Musk for Her. The elegant and hefty Natori Eau de parfum (all right, this one has a "window" in the centre which helps a bit till you're halfway through the juice) or the "opus noir" black ones By Kilian.
Several art-deco retro ones by parfums Ybry, Myon or Gabilla. The opaque gold Cardinal by Molinard with its nude bodies in relief.
Even things like Laroche's Drakkar Noir! And if you're extra lucky to own them, the black polygon of Nombre Noir by Shiseido and the flacon tabatière from 1927 for Liù by Guerlain.
Or it could be any perfume receptable which is intended for you to fill with the scent of your choice, such as ones made by Renaud, Lalique, and other reputable firms. The matter is always the same: how to see when is the time to replenish your perfume? Or just how much fragrance is there in your bottle you intend to sell as filled or to swap? No, tapping to see where the bottle is hollow pr not won't help much. Here are some easy tips to help you.
Method 1: Let the light shine bright!
By now, you probably know that light is the archenemy of perfume and you store yours away from it in a dark cupboard. Good, except for one occasion: When you want to see just how much juice is left in your beautiful bottle. Make an exception and bring out your flacon in the sun on a bright day.
1. Hold the bottle high against the rays of the sun. Even the most resistant bottles provide some clue as to the "line" where the full ends and the empty space begins.
2. If you're short of a handy window sill and the bright sun of the Med, repeat the experiment with a very bright lightbulb (60W or above). Hold the bottle carefully against it. Chances are you will be able to discern adequately.
Method 2: Sinking, sinking...
If the light method above fails, water might come to the rescue. How, you ask? Simple. According to basic physics, immersing any object in water will produce a substitution of the volume of water with the volume of the object (The principle by which throwing a whale in a swimming pool will more than sprinkle spectators three rows of seats away). How do we put this into practice with perfume bottles? First of all, don't try this with anything vintage with a paper label: it will be soaked by the water and the paper will crack when drying. But for modern bottles or bottles that can withstand this, it's unbeatable.
1. Take a receptable that can hold your bottle in question. Preferably use one that is big enough to hold it, but is also shaped in a way that the bottle cannot capsize (i.e. it follows the contours, usually that means an oblong vase or a jug or something along those lines.)
2. Fill it with water.
3. Now slowly immerse your bottle in it and slowly let it go. The power of hydraulics will have your bottle float to the line where it's still full.
4. Mark that line with a small adhesive label which you have at the ready or an indelible felt pen. 5. Get your bottle out of the water, let it stand and see where your marking points: 50% full, 2/3 full or less? You should have a pretty good idea.
These are more or less more accurate methods than just judging by weight, both because one can be fooled by the weight of the flacon itself (especially if it came into your hands in a non full state to begin with) or by the appreciation of liquid itself (the swooshing sound indicates there is liquid inside but it rarely gives a clue as to how much).
Related reading on Perfume Shrine: How to Open Stuck Perfume Bottles
pics via assorted perfume fora, flickr.com/photos/eivinds and 123rf.com