Recently I got to visit the National Theatre's Archive with the ISG London & South East.
The National Theatre has kept archives since it was founded in 1963, but it has only had a "proper" archive since the 1990s, and the current building (the NT Studio beside the Old Vic) has only been in use since 2007. The public reading room is open five days a week, and welcomes around 2,700 researchers each year.
The Archive covers three main areas: the first is the most popular and consists of cultural archives, such as photos, press reviews, stage management reports, programmes, posters, prompt scripts and the costume bible - including, in recent years, high definition photographs of costumes so that they can be recreated later on if need be. Many of these were used during the recent 50th anniversary celebrations. Recordings have been made since 1995 (except where contract negotiations don't allow it) - Platform recordings (where an actor or other theatre practitioner is interviewed in front of an audience) have been undertaken since the late 1980s. The cultural archive is fully catalogued.
The second part is the business archive, including meeting minutes, architectural plans et al: much of this is sensitive material. This archive includes the only plans of the Olivier's drum revolve, as well as information about the founding of the theatre The third part is the external collections: the largest is the Jocelyn Herbert Collection, the archive of the acclaimed set and costume designer, consisting of around 6000 drawings, notebooks and even masks from one of her productions.
As the Archive is part of the Learning department, it can focus on being an academic resource, and not bringing in money. In any case, everything is in copyright so it cannot be commercialised. The Archive aims to support every level of learning: for those of school age, lots of plays the NT has produced are on the syllabus, and many pupils get the chance to take part in Archive Learning Days, in which they see the play and then explore the relevant resources.
The Archive works closely with the Digital Development department: an app has recently been launched with digitised archive content covering the "best" 50 plays performed at the National.
The Archive uses the CALM software, and it is possible to search by production, actor, or a number of other criteria. The press often use the information in obituaries.
The Archive catalogue can be accessed online, and you can also email queries in from the website. Resources are used in exhibitions at the NT, and on the last Friday of every month, the NT Archivist and curator offer a tour of the exhibition in the Lyttelton Lounge followed by a handling session with materials from the Archive.
It's possible to go to the Archive reading rooms to watch a recording of an NT Live or other recorded production: recent popular productions have included Frankenstein and One Man Two Guvnors. I keep meaning to book an appointment to watch His Dark Materials - one day I'll get around to it!