OK, I had a go. Made a few mistakes but this was a learning exercise. I used a design printed on ordinary paper with a laser printer, and for this method you need:-
Ferric nitrate (I got crystals from www.megauk.com)
Distilled water (from Halfords)
Small plastic container (to etch in, so needs to accommodate whatever size you are etching)
Polystyrene (to keep the silver afloat while etching)
Bicarbonate of soda (to neutralize the acid afterwards)
Your design printed with laser black ink
Strong tape (to cover the back of the silver to stop it etching, I used double sided sellotape)
My design was a leaf skeleton print from this photo I took in my garden
In Paint Shop Pro, I copied the section I wanted into a new image,
and then went through these steps:-
a) remove background
b) sharpen (I used unsharp mask)
c) turn into negative image
d) replace the backgound colour (now black) with black (just to make sure it is really black)
e) replace the leaf veins (now white) with white (to make sure it is really white)
f) print the image the actual size you want it to be, using the highest dpi your laser printer will allow
Make sure your silver sheet is clean ( I just used regular washing up liquid and rinsed it well)
Iron the image onto the silver sheet. I put the silver sheet on a block of wood, carefully placed the design on the metal. The iron must be at the hottest setting with the steam turned off.
Place the iron on the paper on the silver and leave it there for at least 2 minutes. I applied pressure throughout. As soon as the silver is cool put it in water to soak the paper. The design was really clear at this point, though there was a strip along one edge that didnt take the ink so well for some reason, but as it happened the silver sheet was wider than I needed so it didn't matter.
The next step is to rub off the paper gently with thumbs. I found this really difficult, the paper did not want to rub off. I re-soaked it many times, and rubbed and rubbed, but a lot of paper still remained. I didn't want to scratch the paper off as I felt the ink would come off too. In the end I gave up and actually it didn't matter a jot.
Next the etching process. In ventilated area, with rubber gloves on and goggles, mix 2 parts distilled water with 1 part ferric nitrate crystals in a plastic or glass container. I did this on the doorstep outside.
I used a black sharpie pen to mark the edges of the silver as I didn't want them to etch away. I put double sided sellotape on the back unpatterned side (to stop it etching away), and then stuck some polystyrene to the back as a float, and popped it in the acid solution for two hours, checking it now and again and tapping the sides to agitate the solution a bit.
The acid solution will keep, so I poured mine into a glass jar with lid for next time. Neutralise the container and the silver sheet and polystyrene with bicarbonate of soda mixed with water. I dissolved a desert spoon or two in about a cup of water.
At this point it looked pretty much like it did when it went in the acid and it was difficult to see how deep the etch was.
Next step was to form the ring. I sawed the edges of the silver the right size and length for the ring I planned to make (with wavy edges).
I bent it round my mandrel and soldered the the join. It soldered well but the some solder came though, and that part of the outside of the ring doesn't have the etched pattern on. Need to think about how I do that bit more carefully next time. When I pickled the ring, all of the ink came off and I could clearly see the etched leaf veins. After sanding, polishing and shaping, I oxidised the ring in liver of sulfer (one drop to anough warm water to cover the ring). After final polishing the etch is cleary visible and exactly how I wanted it to look.
The bit that is difficult to get right is soldering the ring and maintaining the pattern all the way round. Still I am pretty pleased for a first go, and can't wait to use some of the other photos I have of leaves, branches and seedpods in future pieces.