What's the purpose of the comb?

I remember my dad owning a lot of DE razors, but I don't remember any of them having a comb.

This is actually a more complex question than one might think. There are many hypotheses to why the comb was used and gave way to the safety "bar".

The most common theory is that men in olden times did not shave as regularly as we do today therefore would have thick stubble growth before a shave. The "comb" would help comb the whiskers into place allowing the razor to cut through big tuffs of hair where a bar would get clogged.

For this reason Comb razors are often considered to be very aggressive compared to bar razors this is not the case as aggressiveness depends on blade exposure and angle.

The comb much like the bar was designed for safety to keep the blade at a safe distance from the skin reducing the chance of nicks. Some razors at a later date had a bar on top of the comb this was used to stretch the skin before the blade cut the whiskers.

The reason for the emergence of the bar is also a bit debated. The theory is that comb razors where very difficult and expensive to make, all the detail for each "tooth" compared to the ease of stamping out a bar. As safety razors became more common and demand increased it became cost efficient to make bars instead of combs.

Others believe that the "teeth" in the combs were often damaged/bent so the bar was made to keep them straight and later as the razor evolved; the comb became obsolete and was taken out of the equation.

In short the purpose of the comb is to protect one face from direct exposure to the blade. The myths that a comb razor is more aggressive is false, it does however work better on a beard with a lot of growth compared to a bar razor. The reason for the design of the comb is questionable though many hypotheses exist as to why it was made and was replaced with the bar.

I find that a comb allows for a smoother shave as it seems to allow the soap/cream stay on the skin/hair right up to the moment the blade passes. Where the safety bar seems to wipe most of the protective soap/cream off before the blade hits the hair.

Well said, mbwhoosh! :)