This technique can be used for Ambrotypes, Tintypes or glass negatives.


You start with a very VERY clean glass plate, OR a Tintype Sheet OR a black anodized aluminum plate. Blackened metal plates do NOT get treated with this cleaner mix as it’ll damage the glossy black layer, resulting in dull grey images.


A Cleaner recipe:

1/3 Calcium Carbonate (marble, white chalk – powdered)
1/3 Alcohol
1/3 Distilled Water

Take a 1 liter glass bottle and fill with equal parts of the ingredients above. Mix well, then use a clean cotton bud or paper towel to clean your glass until it is squeaky clean. Do not hesitate to use some force but also do not forget to carefully wipe off all excess chalk from the edges.


Then, choose one the following recipes:


Recipe 1 – salted collodion (‘Old workhorse’ by John Coffer)


0.85 grams Cadmium Bromide

0.7 grams Ammonium Bromide

3 ml distilled water

2 grams Potassium Iodide

100 ml grain alcohol (190 proof)

120 ml Plain collodion USP (Not the flexible collodion)

50 ml Ether



In a small glass beaker/ jar dissolve the 0.85 grams of Cadmium Bromide and the 0.7 grams of ammonium Bromide into 3 ml of distilled water.

Using a glass stirring rod mix until fully dissolved. You can warm the mixture over a low heat source if needed.

Add 2 grams of Potassium Iodide and again, dissolve completely

Finally, add the 100 ml alcohol



In a separate container, add 120 ml of plain collodion and 50 ml ether. Mix the ether TO the collodion, not the other way around. Stir well.


Add part A to part B and stir to mix it. Let this mixture sit for several days to allow it to settle. Do not disturb the sediment when pouring off into a small bottle with a screw cap.

Whatever you do – Do not pour this solution down the drain as it will block up your pipes – permanently!



recipe 2 – ‘Poor Boy’/ ‘Poe boy’ by John Coffer (this is what I use)


240 ml plain collodion

300 ml denatured alcohol

6 ml distilled water

3 grams potassium bromide

5 grams potassium iodide



Add Alcohol to the Collodion



Add Potassium Bromide to water until dissolved. Then add potassium iodide till dissolved.


Add part A to part B and allow to settle for a few days. Pour off into a separate bottle with a screw-cap.




Pour this onto the plate, either from the center and then swirl it outwards (like baking a pancake) or let it flow diagonally across the plate from a top corner to a bottom one. Pour off any excess if needed.


Then, in a darkroom (red light or darkness only) place the plate into a silver bath, which could be a horizontal tray, or a vertical bath – which consist of


36 grams Silver nitrate

400 ml Distilled water


Add silver nitrate to water and mix well, then filter it through a coffee filter of something similar.

Before you use this bath for the first time, take a coated glass plate and leave it to sit in the bath overnight, to remove the next morning. The bath is now “seasoned” for use.



Take the plate out of the bath, lets the excess moisture drip off for a second or two and wipe the back with a paper towel. Then place it in a plate holder for your camera, with the collodion surface facing the lens.

All area’s that are moist (wet), will develop after exposure – so depending on the climate you are in, the weather and temperatures on the day – you will have anywhere between 2-10 minutes to expose and develop your plate.


I have found that with my fresh Poor Boy mixture (after 1 week ripening), I get decent results with 8-15 seconds on f5.6 on a cloudy day. Obviously this will differ per camera, per lens and per area of the world you are in.