Our essential oil bottles are filled by weight, not volume.
Essential oils vary in density, which means some are thicker and some are thinner than others. Instead of filling our bottles to make them look full, we fill them to accurately reflect the weight listed on the label. Thick (or dense) essential oils typically have a lower fill line, while the fill line of thin essential oils is higher. The fill level variation is minimal in 1 oz bottles and more noticeable in larger weights.
Always weigh products when making candles, soaps, and other body care products. Avoid measuring essential oils by drops or with measuring cups or spoons, because those methods measure volume instead of weight.
Our 16 oz (by weight) essential oils are packaged in slightly oversized bottles. We thought it would be less confusing to use the same bottle for all of our 16 oz essential oils, instead of using a variety of different bottle sizes for the same weight.
You may also notice that a handful of our essential oils come in 3.5 oz weights instead of 4 oz. Some essential oils were so light that they didn’t fit into the same bottles used for most of our 4 oz essential oil weights.