Carrier oils are just what they sound like when used in aromatherapy. They carry anything that is added to them to the skin. Any essential oil you are planning to use should not be use neat (by itself). They are too concentrated to do that with and could cause an irritation or even a mild chemical burn to the skin. They need to be mixed with a carrier oil before applying.
Carrier oils are vegetable oils that come from the fatty part of plants. Each carrier oil has its own properties and uses. The type of massage or therapy you are having could dictate the type of carrier oil that is used. The list of carrier oils is lengthy but a few of the more popular ones are Jojoba oil (probably number one), Olive oil (rich in vitamin E but can be heavy and leaves a scent), Almond oil (absorbs fairly quickly but leaves an oily scent), Evening Primrose oil (light oil with lots of omega-6, can be expensive), and Sesame oil (good massage oil but should be mixed with another carrier oil, leaves a film on the skin).
Shop for oils that are not heat processed. They should be cold pressed or cold expeller pressed. Being cold pressed means that they have been pressed from the plant without using any heat. Cold expeller pressed means that a minimum amount of heat was created because there is friction used in the processing. Cold pressed oils will have the highest amounts of nutrients and fatty acids and, of course, are the best for your skin. Avoid buying oils that are premixed.
A health food store is one place to look for oils but sometimes their oils are on the shelf for quite a while. If there’s dust on the bottle leave it there. The oil has probably been tainted by too much light and heat. The oils in a health food store can also be more expensive than a grocery or big box store. Ordering them on line can cut the cost more even with shipping.
Cost can vary depending on what processing method is used and whether or not the oil is organic. You’ll have to shop around to get the best price for you. If you buy organic oil be sure the carrier oil is certified organic. Don’t get caught in a scam.
Try different carrier oils to see which one you like the best. You might like a lighter one to mix as a bath oil or face oil and a heavier one for massage and the rest of your body. Carrier oils can be mixed together but do it yourself so you get the exact blend you want…and have fun.