View Full Version : Subtle blue tint

16-Aug-2020, 17:06
I am getting a subtle blue tint on some of my ambrotypes. Cyanide fixer. I suspect it is from that. Is it too little wash, too much wash, my developer? Not enough stop, anyone have any idea? It is only on part of the plate.

17-Aug-2020, 09:16
I'm surprised no one more experienced has answered yet. I'll take a stab at it since I've had this happen as well.
After development, the plate goes in water. If you don't wash it there for long enough, you won't remove all of the developer.
You know it's ready to be fixed when the water no longer beads up on the plate.
Fix it too soon, and some developer stays on the plate, giving the color.

17-Aug-2020, 09:20
Not enough stop,...

Usually this one. Rinse plate completely prior to KCn.

Developer (acidic) + KCN fixer = Prussian Blue and Cyanide Gas. :eek:

17-Aug-2020, 09:29
Randy, this has happened to me as well, and I don't use KCN, just hypo.
Is it the KCN, or not enough fix time?

17-Aug-2020, 12:01
Randy, this has happened to me as well, and I don't use KCN, just hypo.
Is it the KCN, or not enough fix time?

Sorry Ari, I can not attest to other fixers. He mentioned KCN for fixer and pigment blue is a byproduct of the oxidation process of ferrous ferrocyanide salts.

17-Aug-2020, 13:28
Ok, thanks Randy.
In any case, I've had the blue stain appear, sometimes it's blue-green, and I was told earlier that insufficient water bath time was the cause.

18-Aug-2020, 03:27
Thanks for the responses. I’ll double my wash time and vigor and see how that works.

18-Aug-2020, 06:21
I put my tins into a tray of water for a stop bath, rock it back & forth, drain, and repeat several times. I've also added another step. When I take the tin out of the tray I pour some water over it as a final rinse. This has helped.

Kent in SD

3-Sep-2020, 20:14
Improved wash before fixing has solved the issue. Thanks all.

10-Sep-2020, 08:23
This is one of the most asked questions, on the old Collodion forum. Extremely common problem for beginners, the "prussian blue". That's why I still bemoan the loss of Collodion.com, with it's active membership (hundreds of posts a month from hundreds of different people), stickies, and "common problems" areas, all moderated by expert wetplaters.

But we may be getting Collodion.com back....