I have an oil blend, that doesn’t list the ingredient percentages, can I use it to make soap?

It is not advisable to use blended oils in soapmaking. The main fact is because it is very important to know the SAP, or Saponification value for the given oil which tells exactly how much lye (in milligrams) is needed to saponify 1 gram of the given oil. Without paying attention to these SAP values, the soap could turn out lye-heavy (or caustic) and potentially dangerous. For this reason it is a good idea NOT to use blended oils in soapmaking.