Can anyone tell me when sepia prints on card became commonly available in the UK? I am trying to date a number of old family photos and it occurs to me that presumably there must be an "earliest date" before which having a studio photo such as the attached was not affordable by most people. I know that the wet collodion process made photography more mainstream from about 1850, but I thinking more about when having one's portrait taken in a studio became affordable by ordinary people. 1860s? 1870s?
More specifically, does anyone have suggestions on the dates of the attached, perhaps based on the clothes? I believe they are one of two ancestors and their wives, both living in Scotland, one a farm labourer in Forfarshire and the other a commercial clerk in Edinburgh.
