Mixing Blended Oils
Write your recipes down in parts or percentages. Figure out how much oil you need, and base your “parts” on that measurement.
If you buy your oils from a store where all the bottles are the same size, you can measure by the bottle.
3 bottles of rose + 2 bottles of sandalwood + 1 bottle clove
The biggest problem with this method is that it makes a lot of oil, and sometimes it’s hard to find a large enough container. Look for stoppered cruet bottles used for salad oil.
General remarks about blended oils
The longer a blend is allowed to sit the more the scents will “marry”. Blended oils made mainly of blossom or leaf oils may lose their scent quickly if left uncapped for even a short period of time. Adding a little oil from a resin (amber, frankincense, myrrh, benzoin, copal) or from one of the perfumer’s fixatives (vetiver, oak moss, balsam) may help keep or “fix” floral or fugitive scents, but it won’t fix a blend which has lost it’s scent.
Keep your oil blends away from heat and light, which can cause them to oxidize and turn rancid very quickly. A little jojoba oil, added when the blend is fresh, will help keep it from turning. Maximum shelf life for blended oils is about six months. Label and date all your oil blends.