Blotters, also known as scent strips or mouillettes in French, are used by perfumers in the process of creation and by consumers in order to test a fragrance (as an alternative to applying it to one's skin). However, the smell of a scent on a blotter slightly differs from when you test it on your skin, though the key moments are usually preserved.
For a blotter to be convenient in use, it is usually about 4 inches long (10 cm). Sometimes they could be longer, about 5 - 6 inches long and 0.4 inches wide (13-15 X 1 cm). For example, Edmond Roudnitska used blotters that were 7 inches (18 cm) long.
As a general rule, perfumers dip blotters into vials with liquid, thus you can often see how they fold them in half lengthwise. They do it to avoid paper bending when it is wet. For convenience, blotters are often narrower towards one end for easier dunking in a slender bottle as well as for the practical and economical reason of minimizing the liquid consumption. Professional blotters are often creased in the middle and made of a sufficiently dense absorbent paper.
There are no special requirements as to what kind of paper is used except that it is minimally processed and should not be coated; remnants of bleach or dye in the paper might negatively affect the fragrance.
A typical density of 300 grams is good. It is not difficult to buy blotters of many kinds, and we can customize blotters to any shape, just like your business cards. You can also make them yourself from a thick filter or watercolor paper.
If you plan to mix your own perfume composition, it is better to use a thinner paper, because it does not hold the smell for long and you can smell the different phases of perfume much faster. For the same reason, blotters in stores are of a thicker paper for perfume to last longer on them. Store blotters are also wider or even cut in different shapes for ease of application.
If you were given a wedge-shaped "professional" blotter, but your perfume tester is in a spray bottle, do not hesitate to spray the fragrance on a wider part of the strip. It is simply more convenient; there are no strict rules or traditions, except common sense.
If you like the perfume and would like to preserve the smell on the blotter, put it in a sealable bag to save it from foreign odors. You can even press it with a slightly warm iron to refresh the aroma on the strip.
There is a very useful thing for perfumers and perfume bloggers called a "tree", or blotter holder. You can use anything with a clip, like a note or a name clip holder. It is a must have for a professional looking photo shoot session.
If you put your perfumed blotter down on a table, it is advisable to slightly bend its end up, otherwise you risk soiling your work area. You can also write names, notes, or anything else you need to remember.
When you work with unfamiliar substances, when mixing a composition for example, try to apply the least possible amount of it to your blotter; it might be too intense and therefore confusing.