Interpreting labels on photographic glass plates from archive of the studio of W H Warburton, Douglas – follow link to imuseum site:
This particular link brings you to a page of Collister photos. If you erase the word Collister and replace it with another surname (but don’t erase Warburton) you can look for possible images of your family from 1864 to the late 1800s. There are lots of other non-Warburton photos on this site (eg donated over the years from a wide range of sources) but this message is purely about tips to help you decide whether the Warburton photos you might find (and wonder about) could conceivably be from your own family.
The Warburton Studio took over the business (in the early 1880s ?) from Marshall Wane Studio, so the printed versions generated during the 1860s and 1870s were produced on Marshall Wane cards, mostly in cartes de visite (CdV) format.
Using the Collister link above as an example, go to the second row down and click on Mrs Collister on the left. The photo is “the right way round” (ie her dress buttons right over left) but the writing at the top of the plate is laterally inverted. The scratched-on label is “Mrs John Collister 10766”. I chose this as an example because it just happens to be identical to one of the CdVs in one of my family albums. Until I saw the imuseum version, I’d suspected that this was Esther Collister nee Clague b 1831, but hadn’t had any way of proving it. Pencilled on the back of the CdV is the number 10766. I now know that this is the studio index number. These were allocated chronologically and this enables us to have a rough idea of the date that any given photo from this collection was taken. But first you need to be able to read the number (and many are difficult or impossible) and then you need to consult a chart of index number/dates in order to be able to date the particular photo.
As far as I know, no such chart exists. But gradually, over the past few years, I’ve built up a list of examples which I can date to within 2 years---eg by finding images of small children with unusual names and researching their birth years. There are a few examples from 1864 which have actual dates scratched onto the plates, plus one example from 1881.
Here’s my attempt at a rough list using just a few of the examples. The earliest I’ve found is 1128---July 1864. The four digit numbers change to five digits circa 1874:
Hope that will be useful !