Resolving Oily Residue in Homemade Perfume

It sounds like you're experiencing an oily residue on your skin after applying your homemade perfume, despite using 99% alcohol and trying different fragrance oil concentrations.

As mentioned by the staff, a simple mixture of high-purity alcohol, such as Ethyl Alcohol (99.9% , 200 Proof, Research/Perfumer Grade) or Ethyl Alcohol (96% , Perfumer Grade, Low-Odor), and fragrance oil should typically evaporate cleanly from the skin. These types of alcohol are designed to be volatile and leave no residue.

The most common reason for an oily residue in this scenario is the composition of the fragrance oil itself. Many fragrance oils contain non-volatile carrier oils or solvents (like Dipropylene Glycol - DPG) that help dilute and stabilize the fragrance concentrate. While suitable for some applications, these carriers do not evaporate like alcohol and can be left behind on the skin, causing the oily feeling you described. Commercial perfumes use carefully selected aroma chemicals and solvents formulated for clean skin feel and evaporation.

To address this issue, consider the following:

1. Check for Other Ingredients: Did you add anything else to the mixture besides the fragrance oil and the 99% alcohol? Even small amounts of other oils or non-volatile substances can cause residue.
2. Evaluate Your Fragrance Oil: If you only used fragrance oil and alcohol, the problem is likely with the specific fragrance oil you are using. You may need to source a fragrance concentrate or "หัวน้ำหอม" that is specifically designed for alcohol-based perfumes and formulated to evaporate cleanly with minimal non-volatile carriers.

Simply changing the ratio of the same fragrance oil to alcohol will not eliminate the residue if the oil itself contains a significant amount of non-volatile components.