Silver edging on bw darkroom prints

[Jack Robert-Tissot]

Can’t work out what my students are doing to get these silver edges. It’s ilford paper, developer and fixed. Multigrade 4 glossy. Thanks!

 

[MattKing]

Welcome to Photrio.
It looks like fog to me.

 

[grahamp]

Probably a bad safelight - the effect seems too even and not dense enough for paper exposed to room light (though I wouldn't rule that out until a fresh sheet is processed in full dark) . Hand prints on the paper too?

 

[Jack Robert-Tissot]

Probably a bad safelight - the effect seems too even and not dense enough for paper exposed to room light (though I wouldn't rule that out until a fresh sheet is processed in full dark) . Hand prints on the paper too?

The effects are most often on the edges of the paper, not the whole print. Not all images are effected, so I ruled out a dark light as you would see it more often. It’s hard to tell from the pictures but it’s an iridescent metallic effect, I’ve never see. It before.

 

[Nitroplait]

I am afraid that I can't really see the metallic effect in the photos.
However, the only time I experienced a metallic phenomenon on Ilford MG was 30 years ago when I noticed prints (from 10 years before) developed golden metallic surfaces in the shadows. I wrote it off to poor fixing/washing, but it strangely only appeared on framed photographs, my unframed prints from the same period was (and is) perfectly fine.
I am now more inclined to suspect a combination of environmental factors trapped inside the frame, perhaps triggered by less than complete washing.

 

[koraks]

Looks like poor fixing. Are these (very) old prints by any chance? This is what old, badly fixed prints start to look like at some point. Usually takes several years though.

 

[5150Bronco]

How could you fix the fog problem? Thanks.

 

[NB23]

Lol

this is because you went directly from developer to fixer. Or in other words, your fixer was totally saturated with developer.

No, your water stop bath, if you used one, didn’t stop anything and it never will.

 

[warden]

Can’t work out what my students are doing to get these silver edges.

It looks like under fixing to me, although I don't know why it would be mostly around the edges. It's easy enough to test though if you watch the student in question use fresh chemistry and verify their technique. Welcome!

 

[jimjm]

I'd tend to agree that this may be an issue with the fixer, although I've never had this happen myself. I've had problems with fogged paper, old expired paper and exhausted developer, and this doesn't look like any of those.
If your students are using a water stop bath, or exhausted stop, this will transfer more developer over to your fixer and exhaust it more quickly. Since paper substrates are more absorbent than a film base, I think it's more critical to use a stop bath with prints than when developing film.
I'd use fresh chemicals and re-test with the same paper. If it keeps happening, then look at the paper as a possible cause.

 

[Nicholas Lindan]

Rockland Colloid "Halo Chrome": https://rockaloid.com/Halo-Chrome-quart , available from B&H, Adorama, et al..

Looks like the 'toner' got passed around the class - as it expires it becomes a brown/sepia toner depositing colloidal silver.