I've interchanged between Kodak Ra/Rt and Arista or their Silver Pixel kits even in the same session. They all seem to work identically; good quality. Just make sure you're getting the right kit. There are other varieties of RA4 processing out there that I've been disappointed in. These Ra/Rt and Arista kits ARE starter. That's all you need. What you don't need is the replenisher or stabilizer, unless you have an automated roller-transport processor. Drum processing should be done one-shot, not replenished; otherwise you're risking anomalies.