What is the difference between PTFE/red silicone, Red PTFE/silicone and just PTFE/silicone septa material?
the septa are made of two layers, a silicone layer and a PTFE layer that faces the vial's content. The silicone layer could be dyed red, i. e. the red is always in the silicone part, but the whole septa looks red then. Undyed silicone is just white. The inertness comes from the PTFE layer, the smoothness from the silicone layer. The Tmax is the same for all of them.