Calendula originated in the Mediterranean and volunatarily grows all over the world though its heart does rest in that lovely moderate climate. In the wild, calendula flowers all year long and the name Calendula comes from the Latin calendae, meaning first day of the month, in a nod to its regular and enthusiastic flowering.
There is no pressed oil, and there is a distilled oil too, but this is not it. This is a macerated oil, meaning the flowers are picked and macerated in (usually) sunflower oil. This is a highly effective means of coaxing out the bio-active properties of a plant. Calendula oil is an excellent example of this.
For skin care, calendula is considered to be excellent for
broken and varicose veins
bruises and cuts
When incorporating this as part of of a blend, a good place to start is about 25% calendula for 75% carrier oil or mixt of other oils, and this is largly based on cost effectivness. You can also use essential oils in your blend, based on what you are using it for. Some suggestions would be
Although Calendula is GRAS (Generally Recognized As Safe) it's possible to be allergic, so if you suspect an allergy, you should patch test it before using