Dipropylene glycol (DPG) is a solvent to cut your fragrance oils you can use this to make reed diffuser use 75% dpg and 25% fragrance oil or to use in insence cones and sticks. Use 1 part of our fragrance oil to 2-3 parts DPG, stir well. Full instructions can be found on listings for insence cones and sticks.
These are estimates and it is always recommended that you test first in small batches.. Some fragrances dont mix very well with dpg, I have only ever had 2 that didnt but it is always best to test.