thinking more about this… the quality of the stainless, the particular type of paper, and water quality all must have something to with it, right, because… chemistry?
I have very hard water, and far as I understand it, “The mineral in hard water will act as a buffer which will reduce the amount of acid in the water.”( source )
Maybe @rubbersoul79 has softer/more acidic tap water?
If that is the case maybe use distilled water?
I tried on mild steel with water and there was barely a shade, tried again with vinegar and I think I see a difference.
Tried brass with vinegar and could barely see it. I expected a better mark on brass just because copper is quick to oxidize, but maybe because copper is almost a perfect mirror to this wavelength… 
Looks like a constituent of a stainless alloy is more reactive. I’m sure we are dealing with an oxide deposit here.
I’ve got a little over an hour left on an engrave, then maybe I will try the test again with water from the water cooler. Not distilled, but certainly softer (and cleaner) than the stuff from my tap.
I used a normal white paper towel roll from kirkland. Maybe I should also try a test using the cheap u-line c-folded paper towels from the restroom.
I also have no idea what type of stainless steel this knife was made from. It just has the word “stainless” stamped on one side, and no other markings. Pretty sure it was in a box of kitchen stuff that I inherited from my grandma.
Using Alhambra drinking water from the water cooler,
before cleaning:
after cleaning:
darker in the later part of the engrave… after the water has started to evaporate?
the paper towel was wet enough to not char at first, but by the last couple dozen passes it was charing a small amount.
This entire thread is fascinating! Going to be experimenting with some of these ideas.
I’m in Tennessee… moonshine? (
)
Dont you dare, send that to me
Too flammable!
makes one wonder if you could transfer comic strips from the newspaper to stainless using this technique…
Anyone consider trying mineral oil on a paper towel? If the acidity isn’t necessary, and the water evaporates quickly, perhaps this would work? I have no idea, just pondering while waiting on my shipping notice!
What childhood?..We do that every year at Christmas time. (Adults too.)
Silly Putty is a great stocking stuffer. 
The professionally marked logos on my frothing pitchers (yeah, I’m a coffee snob) have faded considerably with repeated washing, so I’m not surprised that this technique fades a bit when washed. However, it should be perfect for items that would rarely be washed.
My mind just went into “idea mode.”
This is ridiculously cool and surprising. Great news!
Me too!
This is a cool discovery! Thanks for posting your results.
This answers a question from a friend. “Could I etch a floor plan?” I had said no, but happy to now be wrong. Every day I read the new threads and my wait for Glowgon becomes increasingly difficult.
This really has me curious, so I asked a couple of people with chemistry backgrounds to speculate on the cause.
Their thoughts:
Today or tomorrow, I’ll give it a try.
Assuming that it is salt, then salt water on a paper towel should work better.
If the water is only there to keep the biomass close to the metal, then kleenex might be better than a paper towel. (My thinking: thinner = closer.)
If it’s really just a need for biomass, then a thin layer of dried mustard (or Brother Mel’s BBQ sauce) will probably be the best option. By removing the water (waiting an hour for the mustard to dry), we might get a cleaner line since there isn’t water to do any refraction.
Then again, maybe dried Elmers glue will work. Dries fast, easy to remove, dries thin, and has biomass.
I can’t wait to play!
