I just posted two instructional videos on youtube on doing a BTZS paper test to determine the toning time for maximum black when selenium toning:

http://www.youtube.com/watch?v=9uvwdsLjXwg

http://www.youtube.com/watch?v=_As1sUQlcHY

It's a very simple test to do. The basic procedure is in video #33:

http://www.youtube.com/watch?v=aHqHN...eature=related

Selenium toning is important for archival processing and increases the density of the darker tones in your print.

This procedure simplifies toning to a time for selenium toning (see the video). Also with modern papers such as Ilford Multigrade IV and Warmtone paper when toning the black will get blacker but there is no color change, so the testing procedure determines the time for toning to produce maximum black.

Any questions, please email me.

Fred Newman