Collections Care and Conservation Policy

1. Introduction

1.1 The collections care and conservation programme at the National Portrait Gallery plays a central role in helping the institution achieve its core aims and objectives, as stated in the Gallery’s Corporate Plan 2017-27. Specifically:

  • To develop the collection, creating opportunities for acquisition and commission, while improving its care and conservation.
  • To bring the buildings, technical and managerial infrastructure of the National Portrait Gallery to the highest standards, including processes, systems, collections storage and staff accommodation.
  • To develop staff as an essential resource through the extension of staff diversity, training, development and learning programmes, upgraded internships, work experience and a volunteer programme.

1.2 The aim of this policy is to provide a clear summary of the Gallery’s conservation and collections care activities and plans for Primary Collection works, as well as those in the Reference Archive and Photographic collections whilst on display, in storage and on loan to its regional partners or other borrowing institutions. This policy also outlines the long-term plan for the care of the Gallery’s Collection and it will follow the professional standards set by the Institute of Conservation. All staff who support and develop the care of the Collection must be aware and abide by this Policy.

1.3 Conservation and preservation of items in the care of the Gallery will be conducted in an ethical manner to the highest possible standards using a risk management approach, as shown in Appendix 1.

2. Scope and responsibilities

2.1 The policy covers the Primary Collection works of the Gallery’s as well as those in the Reference Archive and Photographic Collections and forms part of the Gallery’s Collections Management framework which consists of:

2.2 This is in compliance with the published Accreditation Guidance provided by Arts Council England, the delivery body for Accreditation in the United Kingdom.

2.3 The care of the main archive and library collections is supported by policies required for Archive Service Accreditation, managed by The National Archives.

2.4 The Director of Programmes and Partnerships responsible for mapping and directing conservation in dialogue with the Chief Curator and in alignment with the Gallery’s corporate plan.

2.5 The Chief Curator responsible for maintaining an overview of conservation for the Collection.

2.6 The Head of Collections Services maintains the strategic overview of conservation in alignment with collection management and the Gallery’s objectives.

2.7 The Senior Exhibitions Manager maintains the strategic overview of conservation requirements for exhibitions in conjunction with the Head of Collections Services.

2.8 The Senior Conservation Manager is responsible for programming and planning of the conservation projects undertaken by the painting, sculpture, paper and frame conservation teams and external Conservation contractors - as appropriate.

2.9 The Individual Curator is responsible for advising on the work undertaken within their particular period.

2.10 The Conservator is responsible for undertaking the conservation work for the Gallery, reporting to the Senior Conservation Manager and working closely with the relevant Period Curator.

2.11 The Senior Archive and Library Manager is responsible for maintaining an overview of conservation for library and archive resources.

3. Definitions

3.1 Conservation is a profession devoted to the preservation of cultural heritage for the future. Conservation activities include examination, documentation and interventive treatment. Preservation is the use of passive non-interventive activities including environmental monitoring, cleaning, surveying.

3.2 All of this work is supported by research and education.

3.3 The traditional definition of the role of a Conservator involves the examination, conservation and preservation of cultural heritage using methods that are proven effective in keeping that object/s in as close to its original condition as possible, for as long as possible.

3.4 Conservation and preservation ethical guidelines include:

  • Minimal intervention
  • Appropriate materials and methods that aim to be re-treatable to reduce possible problems with future treatments, investigation and use
  • Destructive sampling/testing (where appropriate)
  • Full documentation of all work undertaken
  • Comprehensive consultation with Curator or Project Leader throughout the agreed/proposed treatment

4. Principles

4.1 Conservation priorities are established based on the following criteria:

  • An emergency situation at the Gallery or whilst on loan
  • Mitigating/minimizing risk to the Collection through the Gallery’s rolling programme of condition surveys, as outlined in the Exhibitions and Collections Corporate Plan
  • Required for temporary or permanent display in the National Portrait Gallery or a regional partner
  • Required for an exhibition or loan
  • Required for a curatorial project, significant treatment or research

4.2 Conservation treatment is usually requested by the Collections Registrar, Curator, Exhibition Manager or Project Leader. Requests are emailed to the Senior Conservation Manager.

4.3 The Gallery will make use of casuals, freelancers or contractors to fulfil the Gallery’s aims; such staff will be ICON Accredited and have previous, relevant experience with a good working knowledge in their specialism.

5. Conservation Examination and Treatment

5.1 Minor conservation, which will not alter an object’s appearance, does not need additional approval by a Curator.

5.2 For all other significant conservation, an examination report is completed before any work is undertaken, in which the Conservator puts forward treatment recommendations. This report is then discussed with the relevant Curator before being formally signed off by both the Curator and Senior Conservation Manager before the proposed conservation treatment commences. The Curator and Conservator may meet during the conservation process and once the treatment is completed the work is viewed by the Curator and the conservation report/treatment is signed off using the appropriate form.

6. Documentation

6.1 Each Primary Collection work has its own individual Registered Packet (RP), within which there is a conservation file, and these are stored in the archives and are normally available to the public on request. Photographs are taken before and after treatment and studio digital images are taken during treatment, as appropriate, and archived with Digital. Hard copy conservation reports are filed in the RP.

6.2 The same process is followed for the Reference Collection – under the ‘D’ Packet system.

6.3 The Senior Conservation Manager maintains a conservation schedule, which monitors the progress of the treatment with start and completion dates. This schedule can be viewed by Curatorial, Collections and Exhibitions staff.

6.4 All works once acquired by the Gallery are photographed and given a full condition report before going on display or into store.

6.5 When a new work is commissioned a member of the Conservation Team (Paintings, Sculpture or Frames) conducts an interview with the commissioned artist, ensuring that relevant information is obtained pertaining to the artistic process and materials used.

7. Exhibition and Loan

7.1 The Gallery maintains a policy of glazing all paintings for display from its own Collection (except for a small number of unusually large paintings) in order to provide protection against accidental damage and vandalism. All works that are either borrowed by the Gallery or sent out on loan are condition checked on exit and entry. Long term loans out are condition checked every 3 years. Long term loans into the Gallery are checked every 6 months, or more frequently depending on object/lender requirements. Exhibition loans in from external lenders are protected by barriers where unglazed as per Government Indemnity guidelines.

8. Environmental Conditions

8.1 The Gallery aims to provide and monitor the environmental conditions in line with current recognized standards in its gallery and storage areas, currently:

Relative Humidity

50% +/- 5%


20°C +/-2°C

Light Levels

Organic material

Oil Paintings

50 lux max

200 lux max

Exhibition Galleries (Ground Floor & Second Floor):

Relative Humidity

Spring / Summer

Autumn / Winter




Spring / Summer

Autumn / Winter



Light Levels

Organic material

Oil Paintings

50 lux max

200 lux max

8.2 Though trials have been undertaken and discussions are currently being undertaken to enable the Gallery to widen its environmental parameters in line with the Bizot recommendations.

8.3 The Gallery’s negative collections are kept in conditions appropriate to their medium: a passive climate for its glass plate negatives; a -20 degrees Celsius freezer for its acetate-based negatives; and off-site environmentally controlled storage (between 7 degrees Celsius and 15 degrees Celsius at a relative humidity of between 35% and 55%) for its nitrate-based negatives at the British Film Institute. An onsite store for cold print storage is being developed.

8.4 Environmental conditions are maintained through the Gallery’s Buildings Management System and monitored through CBRE. Any concerns are reported to the Senior Conservation Manager and Head of Collections Services; regular monthly meetings are held. All data is collated and stored for at least 2 years for the long-term care of the Collection. Natural light coming into the Gallery is controlled through a mixture of blinds and UV film. Light sensitive objects are routinely ‘rested’ to preserve them for future generations. The infrastructure of the building is routinely inspected and maintained to minimise the risk to the Collection.

8.5 The Head of Collections Services reviews the environmental conditions on a regular basis with the Engineering Manager and advises as appropriate to the relevant parties.

8.6 The Senior Conservation Manager oversees the preventative conservation programme of works in the Gallery, the regular surveying of collections in the Gallery, in storage and on long term loan. The works in the Gallery are cleaned and inspected every 6 months or more regularly if needed.

8.7 ‘On the spot’ issues regarding maintenance and cleaning are dealt with through the internal help desk.

8.8 Elements of the Integrated Pest Management Policy have been implemented in areas that are known to be at risk. The Gallery undertakes monitoring of traps in rooms on a quarterly basis, and more frequently in relation to vulnerable works e.g. tapestries and taxidermy. Stores are regularly inspected and cleaned. The Head of Collections Services meets on a regular basis with the relevant Collection Services team members and the Facilities Manager to ensure that the programme of works is undertaken balancing this against available budgets and time frames.

9. Emergency

9.1 In the event of an emergency, the Conservation Team will complete the relevant documentation, an incident or damage report form, and identify the appropriate salvage procedure to mitigate risk to the collection, put forward recommendations and undertake treatment as agreed with the relevant Curator.

10. Advice and Guidelines

10.1 The Conservation Team will seek advice and technical support from external Conservation Practitioners when the specialist nature of the project/work cannot be undertaken by the Gallery’s Conservation Team – e.g. mixed media, Time-Based Media, textiles, metals and miniatures. This support will usually be drawn from other nationals, including recognised specialisms with partners – e.g. Tate, the V&A and the Courtauld.

10.2 The Gallery’s Conservation Team offer advice and support to Gallery staff and to colleagues across the heritage sector including: Museums, Galleries and Freelance Conservators.

11. Research

11.1 Research is fundamental to conservation/preservation work, whether through large projects working in partnership with other organisations, research based on the Gallery’s Collection or as a facilitator of research for scholars from outside the Gallery. Research informs everything from major conservation projects to day to day activities, such as acquisitions, loans, exhibitions and displays.

11.2 The Conservation Team will:

  • Contribute to, deliver and participate in workshops seminars and conferences both internally and externally, with the core objective of sharing research knowledge and understanding of the Gallery’s Collection
  • Continually assess its internal conservation approaches/methods, evaluating developments in the conservation/preservation fields and applying, where appropriate, to the Gallery model
  • Undertake and contribute to scholarly research into historic methods of 16th Century-frame construction. Analysing layer structure - sampling early frames in the Gallery’s Collection
  • Investigate the materials and techniques of artists, using the range of analytical equipment available in the Department (infrared reflectography, X-radiography, UV photography, light microscopy, 3D digital microscopy, Fourier Transform Infrared Reflectography (FTIR), Spectroscopy) and liaising with external specialists/experts. Contributing to the existing body of knowledge on artist’s techniques and materials
  • Research the environmental impacts on the Gallery’s Collection on display and storage - collate data on the display of works and in storage and identify the associated risks. This will include developing maximum review condition timeframes for all Collection mediums with an associated risk profile
  • Review the materials and techniques employed in the climate buffering back boarding system – continued material research

12. Review

12.1 This Policy will be monitored and reviewed every five years or as required by legislative changes.

Edward Purvis, Head of Collections Services
Approved by the Board of Trustees, November 2023
Date of next review: November 2028

Appendix 1 

(on request)

  • PAS 198:2012 Specification for managing environmental conditions for cultural collections
  • The Gallery’s ongoing approach to environmental sustainability (e.g. couriering and packing)
  • Benchmarks in Collections Care for Museums, Archives and Libraries, 2018
  • Principles for Lending and Borrowing, 2021, NMDC/TEG
  • ‘Bizot’ Group Agreement: Achieving sustainability for galleries and museums, 2013
  • PD 5454:2012 Guide for the storage and exhibition of archival materials
  • Codes of Ethics: ICOM-CC /ICON
  • Institute of Conservation’s (ICON) Conservation Register