Monday, January 28, 2008

Hunting

The continuing saga of the litho process, purely to aid my memory


After buffing the gum arabic/nitric acid solution, you let it etch overnight. The next step is to use lithotine (or turpentine) and then laquer thinner to wipe off all the ink, effectively erasing the image.



Once it's off, you rub in a bit of asphaltum (Senefelder's). Buff smooth.




You etch your stone a number of times before you print it. The further an image is etched into the stone, the more prints you'll be able to get out of it. If you're looking to do an edition of 10-15 prints, you need to etch 3 times before printing. Continue to re-etch until you have etched in sufficiently for your edition number. To re-etch, at this point you would wipe off asphaltum with a clean sponge, ink stone, dry stone, rosin and talc, mix nitric acid and gum arabic, rub in, buff with cheese cloth, leave overnight for magic to occur, use lithotine and lacquer thinner to erase image, and rub asphaultum on that again... and so it goes, again and again.
The proportion of nitric acid to gum arabic increases with each etch. For example my first coating was just gum arabic, second had 5 drops of nitric acid per 1 oz. gum. Third etch had 7 drops.



When you're ready to print, you rub off the asphaltum with a clean sponge,



You'll set up the press to the right pressure by fiddling with the top turn key and the pressure bar on the side of the press. Create a stack of papers to act as a "blotter" or cushion between tympan bar and stone. There should be a plastic sheet on top to catch grease from tympan bar.




Run your print through the press, never going off the stone (which would again upset pressure and break the stone.) Make tape marks to show yourself where to start and where to end a pull; you won't be able to see the stone as your moving it through the press.


Finished Lithography Print

Monday, January 21, 2008

Chemistry

Learning a new printmaking process: Lithography.
First you make a drawing with sticks of oil: lithography pencils, onto a block of special Bavarian stone.




Then you rub in a sprinkling of rosin powder, and after rub in a sprinkling of talc power.






When the oily drawing has absorbed the power, making the surface smooth, you mix a solution: a few drops of nitric acid with an ounce of gum arabic. You rub this in for a few minutes.





After that's rubbed in, you wipe off the excess with your hand, and buff the surface with a soft cheese cloth. That's your first "etch" in preparation to print.




Saturday, January 12, 2008

Friday, January 11, 2008