thanks for the info.
I cork my Derbys now with hard styrofoam. I haven't notice any longevity issues at all. I'm still getting 4 wonderful shaves per blade which is more than enough for me. The vertical Derbys MUST be corked otherwise they are garbage for alot of people. But, I just noticed something else by reading replies to this post. It seems as if everyone who uses a 38c likes Derbys, myself included. They must function better in this razor?
I've used probably about 30 derby's (derbies?), out of a pack of 100 I bought when I very first started with a DE. And now that I've tried a few other blades, I don't think I can ever touch one again. I think if you have a tougher beard, a derby blade just can't handle it. They pull horribly on my skin before they actually cut into any hair.
Feathers however....
This is odd as I got a sampler pack and am loving the vertical Derby's. I have consistently used each of my Derby blades for a week before replacing them. These are by far my favorite blade!
I am using a Gillette open comb razor and shave daily.