I did ambrotypes a couple of years ago, painful and frustrating process but if I ever get the chance again, I'm all over it. I have another one on clear glass in Peterborough, but I don't have a photo handy.
ambrotype322 by
shadowedsmile, on Flickr
Done tons of Van Dykes and Cyanotypes over the years...looking forward to doing a Historical Processes class next year.