How was old etching done?

I have a Frederick Reynolds I recently bought from eBay not knowing exactly what I was in for, but all things considered decided it was worth the risk. And it was indeed. One thing that was better than I expected is the etching on the blade. It is a very nice look, simple decorative vine/flower on either side of the multiple lines:

Diamond Steel Razor
Manufactured By
Frederick Reynolds
Sheffield
Tempered by Patent Process

With the light angle just right, this is all very legible. However, it is not as visible as I would like. In trying to determine if there is anything I can resonably do to darken the letters, I've searched this forum and will continue to, but in the mean time, my main question is how did they do this etching then? The tang marking says "Sheffield" and not England, and from the hefty wedge style of the razor itself, and its horn scales, I'm assuming this is pre-1890. I'm hoping if I can understand the original process, I'll know more of what I'm dealing with and have a chance to restore it a bit.

The background on the etched side of the blade is muted...flat when compared to the back side of the blade. Is this a coating still left on the background of the blade? If so, is there a chance I could wash some material (etching fluid...whatever that might be? ink? other?) to darken the letters and pattern even a little? OR, is that muted background the part that has been etched, leaving behind the pattern which was originally protected by some pre-etching application? I appreciate any insights on the process as it was and any thoughts on restoring the image a little.

- Dale

I have a couple of razors just like yours, one of them is a FR with Masonic symbols. Thanks for asking the question, that saves me from having to. J.