Tuesday, 31 May 2011

Etching and Aquatint

I wanted to write down the process for apuatint for myself mostly. I don't want to forget how it is done by next time I go to do it.
Initial sketch.  I liked her feet which reminded me of how Rach sometimes stands. ^-^

 I was originally going to do this drawing in ink and this was a quick sketch to get a general idea. I like how Parker ink splits into several different colours but this makes it difficult to control and can be problematic. After trying aquatint for my cover, I thought i could give this drawing a go as well.
In order to get the solid lines, I had to do an etching first. Above is the outline of my drawing which is numbered according to the time it needs to stay in the acid. Anyway, getting ahead of myself there.
Fist thing that needs to be done after getting the plate to the right size... you might want to leave room for a bleed which I completely forgot about ^-^ ... is that it must be polished using steel wool and then cotton wool. Do not polish it if the zinc plate is the really expensive cool one because the steel wool will damage it. I used the cheaper zinc for most of my aquatints. As far as I can tell, the only difference is that with the more pricey one, you can get brighter and clearer whites which was useful for my front cover. Anyway, after polishing the cheaper zinc plate, it must be degreased and rinsed. When the water no longer bubbles on top of the plate, it is ready. It might take a little while to do this, so be patient. Dry the plate on the hot plate or on the side. Do not use paper towel on it. Once it is dry, you can put the ground on it for the etching. There is soft ground and hard ground, which I will get back to in a sec. The plate should be allowed to warm, you will know it is ready when the ground smoothly transfers to the plate. If it jumps, wait a few minutes and try again. Create two S shapes on your plate, this should be the right amount for your plate. If it is not, do not fear because the rollers have some ground on them already so it will transfer to your plate. Make sure you use the right roller for this, soft roller for soft ground and hard roller for hard ground. Try and get an even layer of mahogany ground on your plate. If unsure, ask. If you used soft ground, it is ready. For hard ground, if is placed under a flame which smooths it out more, removing any spots where the plate might have been missed, and darkens the ground. You will need assistance for this. First time I did it, I managed to drop the plate in the the bucket of sand waiting underneath. It barely missed Laura's hands. I had to clean my plate and redo it all from the beginning. One thing I did forget is that at some point you need to put backing on your plate, brown packing tape or anything waterproof. When the plate in put into the acid, this will protect the back being eaten away, so try to get it smooth. A very affective way is to make a sheet with tape on the table by laying one strip along the edge of the first until you have enough to cover not just the plate but for you to be able to hold onto it. By stretching the tape once you have your plate onto it and banging it onto the table, you will remove a good number of creases and bubbles. This also means that the face of your plate never touches the table so it has no way of getting scratched. After that, simply cut off the excess with a knife and try and remove any last bubbles with your fingers. With soft ground, I believe you can do this before rolling the ground onto it but with hard ground you must wait because of the flame you put it under.
The difference between hard and soft ground is in how you transfer your image (remember that any text must be backwards on the zinc plate for it to print out the right way). For soft ground, while the plate is still warm, place your drawing/tracing on the plate directly and trace using a hard pencil. Make sure you tape down your paper so that it does not move. Where you press, the warm soft ground will lift off and transfer to the back of our drawing. This must be done quickly because as it cools it will be less affective. If it does, you can place it on the hot plate for a few minutes before trying again. This process will give you very thick and yet soft lines. One problem I found is that as the soft ground cools, the lines you draw get lighter so it is best to work fast and to draw your darker lines first. I used soft ground for my cover. Once I was happy with the lines I had, I removed the paper and scratched away at the ground like you would with the hard ground. It was a nice mixture with thick and thin detailed lines.  For hard ground, the plate must be allowed to cool before proceeding. You can then scratch your drawing directly into it. There is no need to press hard for you are simply removing the ground not scratching into the plate. What I did for this drawing and the one where Mouche is sleeping in the car, is that the ground covered plate was placed through the press with my sketch on top. The sketch must be drawn in a very dark pencil, 6B or 8B should be alright. I had trouble getting a transfer with mine and ended up putting it through the press several times but in the end, the graphite transferred to the plate and I was able to scratch it away without having to worry about proportions or anything. For this drawing, I left a bit of it for me to do freehand, like the detail on the puppet booth.
Once you are satisfied with your drawings (if there are any mistakes, you can put stop out on it so that acid can't reach it), look at the chart in the printing room (we have one here at Plymouth Uni, not sure about anywhere else) which has the darkness of the lines related to the time the plate needs to stay in the acid. I'm not sure what the ratio of the acid was, maybe 1:8. Careful not to splash acid on you as you put the plate in. It is recommended that you take your plate out, rinse it, and look at it to make sure you have the right amount or zinc eaten away. If you are not sure, ask. I ended up putting mine in a few times more because it wasn't ready. Because the lines are so thin, the plate needs to be in the acid bath longer for it to print out nice and dark. Remember to come back to it every minute or so to agitate the bath or brush over the plate with a feather. The acid created gas bubbles that need to be removed or the lines won't come out as clearly as they should. Make sure the fan is on to take out all the fumes and that you bring the glass window back down. We don't want any inhaling of any poisonous fumes. :) Once you take your plate out, make sure you rinse it. Use the stick provided to lift it out of the bath and make sure you wear the protective gloves. You can now remove the backing and remove the ground using methane. If you only wanted to do an etching, this would be your stop, the plate is ready for printing. For aquatint, the plate must be cleaned and ... I can't remember if it must be degreased again. Place it on the hot plate to dry. Do not put tape on it's back and if there is any due to etching, remove it!!! Once it is dry, it must go in that chamber with that yellow resin powder thing. Gloves and a mask must be warn and the door must be shut. Brush the excess powder off the wood inside and remove it, gently placing your plate on top but close enough to the edge for retrieval later. Close the little door and agitate the powder and prepare the timer for 2 minutes. Depending how long you wait to place your plate in, the powder dropping on your plate will be thicker or finer. Once the two minutes are up and the plate is removed, the resin must be fused to the plate using a torch light. wait for it to cool and replace the tape backing. Use stop out for the areas you wish to remain white on the plait and place in the acid bath for the darkness you wish to achieve. Do this according to the chart shown on the wall there. It is a good idea to have your sketch numbered as I have so you know what time each section to be in the bath for. As you go along, you stop out more and more of your image until only your darkest and last areas remains. Once it too has been done, wash off the acid like always, and clean the plate using methane. This will take a really long time, it might help to leave some methane on for a few minutes and to come back to it later. Remove the backing and the plate is ready for printing. It does not need to be degreased.
If you plan to print the same day as you prepare your plate, you must do this first but if not, do it as soon as you come in: Place your correct sized paper in the basin and soak for 10 minutes. Remove and blot dry until there isn't any shiny water visible on the paper. Leave to dampen under plastic and wood. the paper needs to be damp in order to pick up all the ink from the groves in the plate.
You might want to wear an apron or soiled clothes. For printing, use the oil based inks. I only used black which is kept next to the hot plates so I don't know anything about the other colours. Scrape the ink evenly onto the plate. With the first cloth, the darkest and dirtiest, make twists with your hand in order to force the ink into all the groves. Then gently wiping away at the ink with the cloths, moving from darker to cleaner as you go along until you have just the right amount of ink left. If the ink is hard to wipe off, place it on the hot plate for a few minutes. For white areas on your print, use a little tissue paper to gently polish the ink away. Place the plate in the middle of the printing press and align the paper so that the print is in the centre. It is advised that you leave a thick edge outside the print, for example, my plate was A5 but the paper I used was A4. Do not move the paper once it has been placed on the plate because this will cause smears. Also make sure the press is not wet at all or this will cause blotches on your paper. Roll through the press and gently lift off your paper starting from one corner. Place to dry, remove your plate, and clean the surface of the press. And you start all over again. You must leave your prints to dry over night. Once you are done, clean your plate and the surface areas.
The zinc plate ready for printing.
Final Outcome after a few attempts.

1 comment:

  1. And now I shall never forget how to do this process ever again...