When I tone I am always using minimum 12 litres of 1:5 and over a session do not notice any exhaustion. After a show or body of work I move to new chemicals.
I also have a temp/humidity controlled darkroom so my chemicals are always steady temp year round therefore I am not concerned about colder or warmer chemicals.
I am only toning Ilford Warmtone and Harmon Digital Paper. and yes I understand different papers give different results , but after a few thousand prints one gets to know a paper.
My toning is based on years of practice and my times are always a result of look I am after, paper I am using and I do not intermix different papers within a show to highlight, lets say a individual image, I print for the Borg , where its all about how the collective group of images look rather than the individual.
I am also a big advocate of fresh chemistrys and I do not replenish any chemicals so this also goes for selenium.
If you are printing for a show, and you want consistent results within the body of images you should stay with consistent times IMO. Otherwise you will have a tonal range difference
when the prints are hung side by side. Remember I only print bodies of work that are to be viewed together and am not printing one shot wonders.
There are blacks within highlights and if you change times within a body of work the blacks will take on different colours if you adjust your times and that is not what I like.
I am doing so much printing of silver and toning that I cannot imagine keeping a replenished jug going, and I have a waste company take away the selenium , the same group that maintain my silver recovery system for the fix. Some of the projects I am working with are printed at different times over a year and therefore I am compelled to use fresh chemistrys. Therefore time and temp process control.
hope this is of interest to you.
Originally Posted by Doremus Scudder