At first glance, it might seem like essential oils simply sit on top of whatever you drip them on, but wood behaves differently. Cedar chips act almost like a sponge for fragrance, drawing the oil inward and holding it there. This is the key reason why sachet bags filled with wood last so much longer than those made from paper or thin botanicals.
When oil soaks into the grain of the wood, it becomes protected from immediate evaporation. Instead of disappearing in a day or two, the scent works its way back out slowly whenever the surrounding air warms up or moves around. Every time you open a drawer or shift clothing near a cedar sachet, you gently encourage more fragrance to lift from the chips.
The thickness and structure of cedar also play a role. Each chip has layers of fibers, tiny air pockets, and natural oils of its own. The essential oils you add blend with that structure rather than coating the surface like a film. Because the chip is doing some of the work, you do not need to use large amounts of oil to make the sachet effective.
Over weeks and months, the scent gradually lightens as more of the oil evaporates from the wood. When you decide it is time for a refresh, the process is simple. A new round of oil soaks into the same chips and you are back to a strong, steady scent without replacing the filler.
This quiet interaction between wood and oil is what makes cedar based sachets feel so dependable. They are not dramatic or flashy, but they keep doing their job day after day, releasing just enough fragrance to keep closets, drawers, and storage spaces feeling pleasantly fresh.