Re: Taming Fabriano Artistico (Trad. White) for Cyanotype
Yes a gritty surface (because calcium carbonate combined with oxalic acid will form insoluble calcium oxalate which is a compound that forms very sharp needle shaped crystals). Do you coat by brush or glass coating rod? You can definitely feel the grit with the glass rod. I had this problem with pop pd too -> cue: both have same light sensitive compound: Ammonium Iron(III) Oxalate... But I don't think that's something related to the sensitizer; since the forming of calcium oxalate is extensively documented in medical texts (it's the cause in 90% of all kidney stone cases), it's the result of combining calcium carbonate with oxalic acid. (Don't eat oxalic acid rich food - parsley, spinach ect. - with yogurt or calcium supplement tablets!) Regards, Loris. 3 Aralık 2008, Çarşamba, 10:08 pm tarihinde, Jeremy Moore yazmış: > Loris, > > What do you meant by oxalic acid causing a gritty surface? Do you mean > the print is gritty or that the paper is no longer as smooth? I've > used it to pre-treat Fabriano Artisitico Extra White Hot Press and > Rives BFK and none of my prints show this with pt/pd or traditional > cyanotype. Is there an interaction with the New Cyanotype that causes > this? > > -Jeremy- > > 2008/12/3 Loris Medici <mail@loris.medici.name>: > >> Because that's what I have on hands. I absolutely refrain from using >> oxalic acid (because it will cause a gritty surface and won't help in >> printing New Cyanotype - tried that before) >
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