Powder and liquid impression material ruled the roost for almost 30 years until tub and tube silicone hit the scene.
Silicone eliminated all concerns of shrinkage. You could throw the silicone impression like a superball and it could still be used for a great earpiece.
One-to-one silicone was next, then in a pre measured format and eventually cartridge impression material.
Cartridges remain the fastest and most convenient way to make an impression. The material has greatly improved. Cartridges offer no variability in mixing and no messy loading of syringes; just a smooth, positive expression of perfectly mixed materials in the outer ear.
Next month the final article about the progression of ear impressions!