This October 1931 Popular Science Monthly article is fascinating. You can find it as bigger images and with a transcript here. When you see that this article is nearly 80 years old and look at the knowledge it contains it tells you that there is no excuse for making a bad razor blade today. This really isn’t rocket science. The only major changes to the DE blade since this article are the adoption of the stainless steel blade by Wilkinson Sword in 1960, which the whole industry then followed, and the use of modern coating techniques using the likes of platinum and PTFE which tend to smooth out the microstructure of the edge.