Recent content by Igor Jansen

Nice! Before going to peroxide there is the first water wash (say 2-10 minutes), which should remove most/all ferric oxalate. The peroxide oxidation can be quite rapid, when using concentrated peroxide (in 3% peroxide its matter of secods, I keep it there for say a minute just in case…)… In...

I would not put the peroxide into tannic acid bath == hydrogen peroxide does not care what it oxidizes, most likely it would just oxidize the tannic acid bath well before you put the paper in… The peroxide in higher concentrations destroys oxalic acid, so in the preparation of ferric oxalate...

Just as a first step you may try to expose paper sensitized only in ferric oxalate (which you have), expose it and wash in water == after this you will see the yellow image formed by insoluble iron(ii)… The peroxide oxidation of this will give you darker brown/yellow image. Ie for first test...

I have just couple, see attached, not a good negative (laser printer, there are spots, where the toner did not adhere well etc.), but it can give you an idea…

There are two points: 1) ferrous oxalate is not soluble in water And 2) it is actually questionable, whether the UV light produces ferrous oxalate at all == ferric oxalate has ideal formula Fe2Oxalic3, ie there is just 1.5 molecule of oxalic acid per 1 atom of Iron. After the UV destroys 1...

Remaining ferric oxalate is washed out in step 3 == in water, similarly to cyanotype... You need to use ferric oxalate, which after exposure produces insoluble Iron(II)oxalate. Other xxx ferric oxalates (e.g. potassium ferric oxalate, AFO etc) produce soluble iron(II) salts, and therefore cannot...

My understanding is that the paper is (sometimes) corroded/eaten by the sulfuric acid in the real iron gall ink (remaining after using ferrous sulfate as source of iron...)

The concentration is not critical for the process, but I used around 20% w/v.

Hi everybody, I want to share a new process, which involves direct "iron gall ink" print without the bleaching of cyanotype etc. Short process description: 1. Sensitize suitable paper with ferric oxalate [only ferric oxalate, nothing else...] 2. Expose the paper under negative and UV light...