Having another go with my Clevedon Pier photograph. This time I used a thinner application of oil for the sky and less etching time. The sky has come out much better, but the shorter etch time wasn’t long enough to allow me to make a decent print. So, I’ll have another go, this time with a longer etch and a similar treatment for the sky.
After my initial experiments with the etching process, I started today to apply what I have learned to my Exmoor tree images.
(See previous etching blog for my first steps in this process).
I opened one of my images into Photoshop, increased the contrast, applied the “Posterise” function and then deleted the background elements I didn’t want to print. The image was then flipped horizontally, and resized to fit the plate. This was then printed on the laser printer. The polished plate was cleaned thoroughly with white spirit, then covered in nail polish remover before applying the printed image, resting gently on the plate while the acetone softens the toner. Then a few layers of newspaper are placed on top of the image before adding a weight and leaving for a couple of hours. Once the weight hs been removed the now dry plate has the paper printed image stuck to it. The paper needs to be soaked off in warm soapy water and gently rubbed away leaving the toner image on the plate. To add some texture to the sky I brushed on some vegetable oil (Thanks Tony Martin – see reference – for this tip).
With the addition of Sodium Biosulfite to the Salt/Copper Sulfite solution to aid the etching process (See Reference), the plate was placed in the solution for 10 minutes, gently brushing away the copper deposits with a feather.
The etched plate was cleaned and used to produce relief prints. However the backround printed as intensely as the tree. (Print on the left, plate on the right).
After a number of trials it became clear this could be controlled with the stiffness of the paper.
It turns out that 200g/sm Inkjet/laser photopaper (Matte) works superbly. Very rewarding morining’s work.
“When I developed my copper sulfate etch in 1992, I realized that mixing sodium bisulfate into the bath to keep aluminium hydroxide from forming, was actually making a weak hydrochloric acid that produced hydrogen in reaction with the metal, which gently lifted the pure copper particles out of the etched lines.”
Today was bringing together my photography and my relief printing.
Starting with a B&W photo with a lot of contrast – An old oak door in Ludlow, Shropshire:
Resized to 150mm on the longest edge to fit my aluminium sheet and printed on a laser printer onto glossy inkjet paper.
Next cut the paper to size, spread nailpolish remover (acetone+alcohol) onto the plate and quickly place, not press, the print onto the plate face down.
Leave to let the toner soften, then put paper towel on top of the image and put a second flat plate on top and weight down (an old iron doorstop).
Leave for a couple of hours.
Now take the plate with paper print attached and soak in soapy water to remove the paper. If all has worked – and it had – the toner remains on the aluminium.
The etching solution is 50g Copper Sulfate (amazon), 100g Salt in 500ml of water.
Cover the back of the plate with duct tape to protect it.
OUTSIDE – put the plate into the etching solution for 5 mins, gently brushing away the copper that gets deposited on the plate where the exposed (no toner) aluminium dissolves in the copper chloride. Lots of heat, gas and smells.
Remove plate, rinse well in lots of water and clean with nailpolish remover to remove the toner.
Lastly ink the plate as for linocuts and put through the roller press with fine Japanese paper and use a felt mat on top of the paper.
Whilst there is room for improvement (in the quality of the initial laserprint, the toner transfer process and experimenting with etching time), I am encouraged enough with the outcome to explore this further – especially for atmospheric landscape images.
(See blog of 7th Jan 2019 for further developments)