Another etch consists of electro etching, which can be done with as little as a 9v dry battery and salt water, this method works well on steel and I find it good for fine work including writing.
The process is mask the metal with a suitable etch resist, I find beeswax works for me, but experiment yourself to find what suits you.
Then scratch through the beeswax with an implement to create your design and remove the wax where you want etching.
Taking a 9v dry battery a bit of wire and a couple of croc clip, make a lead up so a croc clip is on both positive and negative leads.
Attach the positive croc clip to your blade and with the negative lead, attatch that to a Q-tip thing, those cotton wool buds on sticks, attach so the cotton wool is clamped.
WARNING ; Do this in a well ventilated area, i.e. outside if possible and don't breath over what you are doing, because the byproduct of this process is chlorine gas and I'll tell you getting a whiff of that one's eyes do roll as Chlorine is deadly, a poisonous gas, best not breathing it.
Dip the Q tip in salt water then rub it over the design on the blade, you will hear fizzing and see a bit of steam and the salt water residue will go greyish black, keep the q tip moving and dip in salt water often, really, when the tip starts to get sticky with the metal as it dries out. Through the process you will need to change the q- tips often, as they do harden and burn, but hey they are cheap as is this method, but the cheapness does not reflect the results.
I test success and depth of etch by scratching with a needle, it catches, I know etch has occurred and I can wrap up.
And I have tried with a bigger battery, a 24v cordless battery, what I found was well the etch was fast, but it was not as controlled and I was forever changing the cotton wool sticks so I concluded 24v was too much for what I knew already worked with 9v.
Also you will notice the croc clip attached to the q tip will degrade fast and rust out if you have a steel one that is, also when manipulating the q tip during the etch grip onto the plastic shaft of the q tip, not that there is the shock potential with so low a voltage, but the process can't do your fingers any good if the electrified solution comes into contact, not that I have experienced anything untoward, but good practice and all that.
Edited to add practice on other stuff first so you get the idea and work out your own method of manipulation. but when I first got this method of of British Blades, I went mad and etched everything, including stuff at work, circular saw blades that received the company logo, as this process can take literally minutes to do
