Wet Plate Collodion questions answered here.

[Mark Sawyer]

Rock the plate as you drain the collodion off, so it doesn't all flow in the same direction. The phenomenon is called "corduroy lines".

[AlexGard]

If you’re making Old Reliable but omitting the additional Ether, then the Collodion is too thick and will not flow correctly. Why omit the Ether from the recipe??

Quite the opposite. The collodion is super watery. I noticed when mixing it the merck collodion is a lot more of a watery consistency than the scharlau collodion I usually get.

I can only get denatured ethanol. I have tried mixing old reliable with ether and denatured in the past and there seemed to be some clash between denatured and ether.

Etherless old reliable has never been an issue for me in the past.

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[Andros-zz]

Hello, friends and colleagues!
Please tell me why a white coating may appear on the surface of the plate after drying, which can be wiped off with cotton wool. I read that this happens from fresh collodion, from excessive alkalinity or acidity of the silver solution, from elevated temperature, or from a contaminated silver bath. I gradually changed all the parameters, but the white coating still appears. Please advise what else can be done to improve the situation.

[Coastie]

Alex,

I have found an Australian supplier of 95% proof alcohol.

It's not a cheap drop, but it might be worth it to try it and see if it helps?


https://www.harrisorganicwine.com.au...e-alcohol.html

[paulbarden]

Hello, friends and colleagues!
Please tell me why a white coating may appear on the surface of the plate after drying, which can be wiped off with cotton wool. I read that this happens from fresh collodion, from excessive alkalinity or acidity of the silver solution, from elevated temperature, or from a contaminated silver bath. I gradually changed all the parameters, but the white coating still appears. Please advise what else can be done to improve the situation.

Wet Plate Collodion images always have a powdery pale surface texture in areas of most exposure (whites), and this is normal. If you burnish the plate, you can easily remove this whitish surface layer, but it is a normal component of the wet plate image and (under normal circumstances) should not be wiped off before varnishing. This powdery surface material appears over the whole plate in areas of greatest exposure (none in the shadows, more in the brighter areas), as opposed to silver contamination, described in the following paragraph.

There is a secondary type of "white coating" that is described as Oyster marks, and this is the result of previously exposed silver being deposited on the plate from a contaminated plate holder. To avoid this effect, clean your plate holder every time, between plates, to remove any liquid silver nitrate from the holder. Oyster marks don't typically cover the whole plate, but instead are irregular marks around the edges of the plate.

This Reddit page shows an excellent example of Oyster marks on a plate.

Question: if you wipe this powdery surface coating off, do the brighter areas on the plate become very mirror-like? (Silver reflective) If so, then you are wiping off the normal surface coating that is inherently part of the image. It's normal. Don't worry about it.