Concentration of bleach when doing selective bleaching

[Ghostman]

Hi there,

I am a fan of bleaching and toning my prints, it works well with a certain style I've developed. I use a very dilute solution and submerse the entire print until I think it's ready to come out for further toning. I would like to try my hand at selective bleaching using paintbrush. What concentration of bleach would one use for this? I have seen videos of printers doing this with the wet print stuck on a splash plate, hose in one hand and paintbrush with bleach in the other.

Obviously different bleaches will require different dilutions. I have a bottle of Moersch bleach that I will be using.

Any feedback, help & tips would be appreciated.

 

[Ghostman]

Bump. Anyone got any information on this?

 

[Ian Grant]

I did a lot of selective toning, some suggest using masking materials I preferred using paint brushes, by using a rehalogenating bleach you can redevelop if needed.

My method was to have a stock 10% bleach solution (rerricyanide & bromide) and then dilute a small amount 1:10 (1+9) so 1%, then dilute this again as needed testing on test prints or scrap prints. The actual strength needed really depends on the paper and the amount of bleaching wanted.

1% is normal working strength so 0.1% is a starting point., I'd add few drops of the stronger solution if I needed it slightly stronger.

Ian

 

[Ghostman]

Many thanks Ian.

 

[Rafal Lukawiecki]

I picked up my method from John Sexton. I have two bottles in my cupboard, part A and B. Part A has a solution of 18g/l Potassium Ferricyanide and part be has 150g/l of Sodium Thiosulphate. They keep well, I am using two year old ones at present, I probably should change them.

When I want to bleach, I mix some (usually 40-60 ml) at 1+1 proportion. This usually works very well for me, but if I wanted a faster working one I'd add more thiosulphate.

Once mixed, it is active for 5-10 minutes. Make sure to remember to refix the print afterwards. If you want to see how John does it, have a look at the 4th photo in the article on my blog: Dead Link Removed

 

[Ghostman]

Many thanks Rafal, this is great info

 

[Doremus Scudder]

I only selenium tone my prints to achieve just a hint of warmer tone.

I selective bleach occasionally to bring out highlights in the print. I use a ferricyanide/bromide rehalogenating bleach. Below is my method, cut and pasted from my personal darkroom handbook.

Note: this technique turns silver into “invisible” silver bromide that needs to be fixed away.

1. Prepare a dilute ferricyanide/bromide solution of about 1 to 2% by adding 10 drops of 10% ferricyanide solution and 30 drops of 3.2% potassium bromide solution (I have these on hand always) to 10ml water (or mix the appropriate dilution in larger quantity, basic solution is 1g pot. ferricyanide and 1g pot. bromide / liter). This solution is a starting point and can be strengthened or weakened as needed.
2. The print needs to be fairly free of fixer, i.e., well-washed before using this technique. 15 min.or so in water should do the trick.
3. Lay the print on an angled work surface, (e.g. the bottom of a flat-bottomed tray). Position the print so that the run-off does not flow over areas of low density that should not be bleached. Working with the running water hose in your left hand, apply the bleach locally with a brush or cotton swab (Chinese calligraphy brushes work well. Don't use brushes with a metal ferule, as this can cause unwanted reactions and staining). Work from bottom to top and monitor the bleaching carefully. It is very important to keep the water running on the print directly below the area being worked on to prevent streaking by the run-off and to keep the water hose moving to keep the bleach from being directed down the edge of the water stream and causing streaks there. Before the desired tone has been reached, rinse well. It is better to build up to the desired tone slowly to prevent over-bleaching, keeping in mind that the bleaching continues for a while after rinsing. Be careful that the bleach is not working too quickly. If so, rinse the print thoroughly and repeat with a weaker bleach solution. Overbleaching can cause split toning!
4. When the desired tone has almost been reached, rinse the print thoroughly to remove all the bleaching agents before fixing.
5. If the bleaching process goes to far, the print can be returned to the developer if bleaching has gone too far, but this will result in a different size and shape of silver grain being formed from the original development, which will tone differently. If redevelopment is necessary, keep toning to a minimum.
6. The print now needs to be fixed to remove the silver bromide produced by the bleach. Give it a full-time fix in the second fixing bath (i.e., 2 minutes in fresh fixer)
7. Wash and dry as usual.

Have fun,

Doremus

 

[Bob Carnie]

I use a very dilute solution and use cotton swabs , q tips and brush.. one thing is to have the area you are working on a slant and a squeege nearby and hose with running water.

It is very easy to get lulled into thinking the bleach is not working and start over concentrating or leaving it on too long.

I squeegee the print, apply bleach where I want it and immediately wash off, in fact I have the water running below the area I want to affect so there is no drip down .

remember to re fix after this ...
A bit of practice and you will be a pro.

 

[Ghostman]

Excellent, thank you Bob. I am looking forward to experimenting and learning.

 

[DREW WILEY]

I just use ordinary Farmer's Reducer 1:1. Some paper/dev combinations obviously respond better than others in terms of holding image tone
in the bleached area. I put the print on my big slanted plate glass squeegee board at one end of the sink and have a little hose beside this
with running water. The print is treated wet, but squeegeed off first, using a selection of camel-hair watercolor brushes, with any bleach
runoff removed by the running hose so that it doesn't affect other parts of the print. Then the print needs to be re-fixed afterwards, prior to
final washing.

 

[Mark_S]

For selective bleaching I take some fixer, and put it in a baby-food jar, then add a pinch of potassium ferricyanide crystals and mix it together. I brush it onto the print with a chinese calligraphy brush (the bleach eats the metal ferrules on normal brushes), and follow quickly with running water. I prefer a really dilute solution and patience since you can ruin a print quickly with a strong bleach solution.

 

[Ghostman]

Thanks everyone for your tips and recipes.