Fix bath toning the color of the print to sepia and losing contrast

[itsskin]

Hi guys!

What can cause the print turning to sepia tones and losing contrast after paper is placed in the fixer?
Here are before and after...

Fixer composition:
Sodium thiosulfate 200g
Sodium metabisulfite 20g
1L of water.



Thank you!

 

[koraks]

What can cause the print turning to sepia tones and losing contrast after paper is placed in the fixer?

1: The presence of any traces of a bleaching agent such as ferricyanide. You can usually see this however since it'll color the solution yellowish. Minute traces of C41 bleach may be more difficult.
2: Print-out processes such as solar prints tend to bleach back dramatically during fixing.

Perhaps you should tell us a bit more about your processing and the materials used.

Sodium thiosulfate 200g
Sodium metabisulfite 20g

Any particular reason for using this relatively slow and low-capacity fixer? You are aware that rapid fixer concentrates are very economical in use, wash out of the paper better and are overall more convenient?

 

[itsskin]

This photo is taken directly on paper and reversed with second light exposure. Reversing is done with bleaching, so this can be the case. Second development was done in VERY diluted developer to preserve shadows going completely black. If I would let it "fully" develop - fixer is not ruining the print.

Considering the process, I might be able to skip fixer all together...

Fixer - simplest one to make myself. Developer, Bleach, Whitening, Stop and Fix are all DIY

 

[Rudeofus]

With the process you describe you get tiny silver particles, which will happily etch away in this acidic fixer. Use Sodium Sulfite instead of Sodium Metabisulfite and see, whether the problem goes away.

 

[itsskin]

This is so far most helpful suggestion.
Same 20g will be enough?

 

[koraks]

Considering the process, I might be able to skip fixer all together...

If you want the print to last, I don't think this is going to work.

Maybe the neutral fixer will help a little, but I doubt it. It's worth a try, but I think you're better off changing your reversal process so that it generates a more robust image. It's not too difficult; I played with this on a few occasions and it's relatively easy to make an image that withstands fixing even in a strong fixer (making good positives of desired contrast, however, is always a challenge!)

 

[Rudeofus]

This is so far most helpful suggestion.
Same 20g will be enough?

Yeah, 10-20 g/l should do the trick.