Selenium is one of my favourite chemical toners for darkroom prints, so much that at the moment pretty much the majority of my prints are toned with it. I love its flexibility, and depending on your paper choice – the colour change can be as subtle or dramatic as your vision for the print dictates.
Now one of the main reasons to use selenium is to increase the archival permanence of the print. The toner will react with the silver in the print emulsion to form silver selenide which will give protection to the print. I’m not too concerned about my prints lasting hundreds of years at the moment – I tone in selenium mainly for the aesthetic, but a more stable print that is less likely to degrade overtime is a bonus.
I use Kodak Rapid Selenium Toner, it’s fairly cheap and the liquid concentrate lasts forever. There are other toners available from the likes of Ilford, Fotospeed etc which i’m sure are equally as good.
One of the great things about selenium is that toning can be done straight away after a print is (fully!) fixed. Keep in mind though – especially if you prefer to tone in a separate session that selenium toner contains fixer, so you will also need to make sure your print is thoroughly washed afterwards to avoid staining (i.e. hypo clear followed by a full wash).
The concentrate is diluted down to strength for required for desired effect.. I keep 2 mixes made up all the time in my darkroom 1:10 for subtler tones and 1:5 for more dramatic colour shifts, discarding and making up a fresh solution whenever toning times start to get excessive as the toner gradually exhausts (for me thats anything more than 10 minutes)
Regarding the effects, below is my experience. You will want to experiment yourself with different papers and dilutions etc, but this should give you a ball park.
1:20 – out my experience next to no obvious colour change, although it was will remove the green cast in the mid tones you get with a lot of papers and a slight deepening in the blacks. (Once you’ve seen this green cast by comparing untoned and toned prints you will not un-see it going forward!)
1:10 – now things get more interesting. This is my default ratio for Ilford Multigrade Classic fibre base papers.
You will get some additional density added to the blacks from the selenium which I find gives a nice contrast boost without the expense of blowing out the highlights.
By keeping the print in the bath longer to tone through to mid tones, I find a pleasant reddish hue is added to the middle grays that’s subtle enough and not overpowering. Warmtone papers will have a more obvious colour shift, and may go light brown.
1:5 – at this strength we get more striking tonal shifts, you will find a more dramatic colour change with warm tone papers. I typically use this ratio for Ilford Multigrade Warmtone papers, which will exhibit very warm browns but I do I find that the MG Classic paper further extend the red hue to subtle purple “aubergine” tones in the shadows at this strength.
Selenium works from the shadows up through the highlights so split tone effects can be achieved by toning to get the desired colour shift in the shadow areas and then toning further in another toner such as Gold or Sepia. I love gold toner although it is wickedly expensive, but I find the complementary tones of warm brown shadows from selenium with colder blue highlights from gold toning pretty special.
Right lets be clear here selenium is toxic.. mixing up your own DIY toner from powdered selenium should be exercised with extreme caution, and quite frankly in this day and age you don’t need to do this considering how readily available good quality, liquid toners are.
The main point is don’t be put off by internet talk about how dangerous this stuff is. Like all photographic chemistry keep it out of the way of kids and animals, treat it with respect and basically don’t drink it.
Wear gloves – seriously, you don’t want this stuff on your hands. Wearing gloves not only protects your skin but gives you the added benefit of not having to use print tongs to handle the print. I have a pair of very cool, black marigolds. \m/
Fumes – in higher strength dilutions these can get a bit heavy. I dont have additional ventilation added to my darkroom so instead keep a door open to get some airflow. It works for me. You can even do this outside if you prefer and you are lucky enough to have nice weather.
You’ll find selenium will stain everything it comes into contact with so give trays etc a good clean afterwards. I prefer to use a couple of dedicated trays marked purely for selenium!