I've been doing a fair number of Ambrotypes lately and have been thinking of hand-coloring some of them. This was a very common practice in the 19th century, but seems fairly rare today. I was wondering if anyone knows of a resource for information on this? A fairly extensive internet search yielded one semi-practical result, but dealt mostly with coloring tintypes:

http://www.thevictorianphotographer....lodion-images/

Anyone know of other information out there? Thanks muchly!