ETCHING
Etching, simply put, is a process by which a protective layer( usually wax and bitumen) is applied on a metal plate ( zinc for our class, and most common) lines are then drawn on it and the plate leave in nitric acid for sometime. The acid will then 'bite' into the metal surface where the lines are and ink is applied for prints.
My camera broke down in the beginning so I only have one image to show! Oh well....
We have done the hard ground and soft ground and I will divide the process up in two for ease of reference.
HARD GROUND PROCESS
1. Take the pre cut zinc plate and file off its 4 edges with a file at a 45 deg to take off the sharp edge
2. Polish the zinc plate with 'Brasso' and a soft absorbent cloth ( cotton) to get rid of the grainy surface ( the plate looks smooth and shiny but it is not, if not polish the grainy texture will make the background grey, but some people may actually prefer this) Polish this twice should be sufficient.
3. Degrease the plate to get rid of the oil on the next step - the wax won't stick. Use soft cloth( old etching blanket), whitening powder and a few drops of ammonia. ( there are also other alternative that comes as a cream and less toxic and smelly) then rinse with water, aim to have no residue.
4. Dry the plate with hair dryer
5. Once dry put on the hot plate (70 deg) and apply the hard ground wax by rubbing and twisting, then use the roller to apply it flatly until you get an even marmite looking layer. * Clean the roller with white spirit and roll on newspaper to clean it.
6. Can smoke the plate with the tip of the flame, make sure not for too long, only lightly and quickly so to darker the wax for drawing on.
7. Now draw on with etching needle, can use stopped out ink to correct any mistakes, or have to do from step 3 again.
8. Now create a pull handle with masking tap to pull the plate out from the acid bath and a sticky back to protect the back of the plate so the acid doesn't thin out the plate too much.
9. Immerse the plate in Nitric acid ( 1:8 strength ratio, note if the acid has been used too much the strength will be less too) for 8 minutes. Ensure ventilation is on, Make sure wear glove, mask and gloves, can use the feather to lightly brush away the bubbles that may collect on the surface too much. ( More so for copper plate, zinc should be less of a problem) RINSE the feather afterwards.
10. After take it out and rinse with water, then white spirit to get the metal surface or printing
11. In the meanwhile, soak up papers(200 gsm minimum, usually good quality is 300 gsm somerset)and use blotter papers to blot out excessive water
12. Ink up plate with intaglio ink, use rubber or card board to wipe over the whole surface and twist and rub in with hard 'squeens'
13. Prepare on the Press first a piece of butter paper on the press, then with metal plate facing up, then the blot out paper, then tissue paper to protect the blanket on top.
SOME TIPS
a. Could also use the dry point method, to draw directly o the metal plate to skip the acid step, but this won't last , may only get 3 editions of the image.
b. can tell the difference between soft and hard ground by trying to dig the nail into the piece, soft ground - nail can be dug in
c. People use copper plate and leave in Ferric acid, it takes longer but the lines are finer than the zinc plates, but because it is slower it is also easier to control.
