Many people will swear by blended refrigerant but they have a huge negative. Each one depends on a balanced mix of whatever chemicals it started with to properly perform. Since all the components have different properties, each part will leak out at a different rate if the system is not 100% gas tight. Even a small 50 gm leak could be 40 gm of one part, a few gm of something else, and none of some other component. You're left with something different than what you put in. That may not sound like much but it may affect its ability to carry lubricant through the system.

R-12 (freon) and R-134a have known properties and can both be recovered if kept pure. Blends are called "contamination" and taken out of the recycling loop when the car goes to heaven.

You do not say what year your car is so I do not know whether you have a Freon (R-12) system or R-134a.