This is one way to do it,,though there are other ways to transfer a printer copy:
Working in B&W and on an InkJet printer..
I've never been picky about the paper or the type of inkjet cart. I'm not a techy, so whatever I have,,I use.
First make a large copy of the image you are going to be engraving,,this one is for 'looking at' while working.
Set that aside.
Then flip that image on your computers photoshop software so it's a 'reverse' or mirror image. This is the one you will be laying face down and transfering so you want it to be a mirror image of the original.
Next size the mirror image to fit whatever space you need it to fit into on your work.
This takes me some experimentation with dimensions (again, no tech here), and I use a circle or oval template to estimate wether the figure will fit into the area I need it too go.
Another thing to keep in mind is when the figure gets very small, try to keep it as uncluttered and simple as possible.
Adjust the light/dark,,tones, ect on the computers photoshop to get the image as dark as possible with the background as white as possible. You want to transfer a black line drawing of the image,,thats it.
When the image is the correct size according to your template or measurements, it looks nice and crisp,,light and dark,,,,print out 3 or 4 copys.
Leave the computer set up still,,you may need more copys if you mess up the next step!
Take a copy and cut it out of the full sheet of paper so it's down to a small managable size.
Place small pencil dot or hash marks on the back or even folds to the paper that bend around the edges of the metal part being engraved so you can easily allaign the paper pattern onto the metal in the exact location you need it.
Remember you will be placing it face (pattern) down onto the metal, so you won't be able to see the pattern now.
Once you have it allaigned,,now for the transfer. For this you use acetone.
A Q-Tip dampened w/acetone is your transfer tool.
Wet the Q-Tip,,shake off the excess and then wave it around a couple of times and you're set to go.
Wipe over the metal surface quickly with the Tip to clean it first of any fingerprints or oil.
Then immedietly:
With the pattern held tight against the metal with one hand/fingers,,quickly swipe over the paper with the Q-Tip. It'll dampen the paper instantly.
What happens is that the inkjet printing ink compound is loosened from the paper and is transfered to the metal.
It takes some practice to get a nice clean transfer. I usually swipe the Q-Tip back and forth a couple times and then lightly rub the paper with my forefinger. Then remove the paper pattern.
Too much acetone or too little will result in a poor transfer. A pattern that is blotchy in appearance is usually too much acetone but it could also be a transfer that has too much inkjet 'ink' on the pattern. That comes from a very complicated figure being reduced in size too far sometimes.
Experiment,,go back and make additional copies and try again.
Once a nice clean transfer is on the metal, it takes well to handling. It will not smudge or swipe right off as you are working like a simple pencil line will.
Remove a bad transfer or any remnant of one when you are done with the acetone Q-Tip again.
Take the normal precautions with acetone. Though you are not using a lot of the stuff, none of it is much good for you.
Color originals can be used to make simple B&W copys and work fine.
Keep copyright laws in mind when lifting images of others work. You don't want to become the focus of a lawsuit. Respect other artists work and efforts.
There are books (soft cover and hard cover) full of non-copyrighted images that can be used. I make full use of these!
Your own photos can be scanned , cropped and used. Remember you are just needing a simple B&W line drawing in most cases.
Hope this helps.