The difference between the STANDARD, EVOLVED & PREMIUM Cartridge Needles.
Materials of needles are different - Premium cartridges come with needles made from better 316L stainless steel & better plastic tips with less impurity, which are betterh than Standard and Evolved cartrdige needles
Soldering - Premium needles are soldered extremely well on bars, every piece of tattoo needle is soldered well and grouped in very good shape. E.G. 9 Round Shaders, the needle head is in perfect ROUND shape with 1 needle soldered in center and 8 needles around it with same space.
Besides the color difference of the tips - Evolved cartrides come with tips which are slightly different than Standard & Premium cartridges. Magnums are close-mouthed. Round liners and Round shader come with bevel tips.