Does anyone have a source for BROWN ferric ammonium citrate? I have plenty of green crystals, but see no reason the brown ones won't work as well and they should be less costly.
I've seen it mentioned (and thus take it as unproven) that the brown crystals are less "light sensitive". So for applications like Cyanotypes they will work but not as well as the green ones. But for other formulas (bleaches?) I don't know.
That said, somebody like Fischer or Alpha or ScienceLab.com should have it.
I've used both brown and green for cyanotype and van dyke prints with no discernible difference. I purchased the brown form from Sigma-Aldrich. They have various suppliers/purity levels to choose from. To find it on their web site, search for "ammonium iron III citrate".
I purchased brown FAC from B&S just recently. You have to ask for it specifically when you order the regular FAC. it is not actually listed in their price list. I believe I added that I wanted Brown FAC somewhere later in the order process.
I've made up some Brown FAC VDB sensitizer and my initial tests were very disappointing. I was not getting nearly the same dmax as with the regular FAC printing the same neg under the same conditions. But I'll give it another go.
Dana Sullivan at B&S has very good things to say about Brown FAC.
I purchased brown FAC from B&S just recently. You have to ask for it specifically when you order the regular FAC. it is not actually listed in their price list. I believe I added that I wanted Brown FAC somewhere later in the order process.
I've made up some Brown FAC VDB sensitizer and my initial tests were very disappointing. I was not getting nearly the same dmax as with the regular FAC printing the same neg under the same conditions. But I'll give it another go.
Dana Sullivan at B&S has very good things to say about Brown FAC.
Thanks for the answers.
Actually I heard about the use of brown from Kevin Sullivan but had not been able to find it. I will check out the referred sources.
Jim