re:gum printing without dichromate

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From: Jean Burdett (jburdett@chariot.net.au)
Date: 12/30/00-01:29:20 AM Z


There was some misunderstanding of my initial message. i was'nt printing on to glass,I was printing on to canvas. For the leaf photogram i placed a sheet of glass on top of the gum treated canvas (instant coffee,water and gum), and placed the leaves on top. I have read somewhere on the net ( i'll give you a reference if I find it again) ,that untreated gum arabic has some tendency,on its own , to harden in the sun. I thought that if that was the case that by taking more time and accepting a poorer result,I should be able to make a photographic print whithout using any chemical too toxic to put in my mouth. It seems I was right. Any sceptics are wholeheartedly invited to try it for themselves. It took 6 to 8 hours of australian summer light. I did'nt produce a great image, but the leaves were quite recognisable.

 I tried making a similar print using prussian blue pigment instead of coffee. I understand it is made with similar chemicals as used in cynotype printing. I don"t know if that is relevant. I thought that the image would appear when the unhardened gum was washed off. That did'nt happen. When I removed the transparency,there were uneven patches of hardened gum. Within the hardened patches there was an image. Some parts were hard and blue,some parts were hard and clear. I do not understand why I got the result I did. I can only presume some process that is not usually part of gum printing took place. The image washed off under water. I will repeat both experiments and keep the evidence this time.

 Randell Webb, you commented that it would be a breakthrough to produce a dichromate free print. I guess that might be true if someone could produce a quality image. I have done no such thing

Birdie

                                   Birdie


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