Tips+Tricks: Preserving photographs with Cheryl Jackson

Photograph conservator at the National Archives of Australia, Cheryl Jackson, offers CAN Partners four steps to caring for photographic collections. She also illustrates how an image can be conserved by hand compared with one preserved digitally using a photograph from her family album. Cheryl is a practicing photo conservator and also teaches at Australia’s leading photographic conservation course at the University of Melbourne. This guide to preserving photographs can be downloaded from Sector Resources on the CAN website.


Photo before treatment. It may not look like a photo, but it was just heavily overpainted as was the fashion of the time.

Step 1 Recognise and assess the more vulnerable forms of photographs
The earlier processes of “printing out” are the most vulnerable to light and most at risk when exhibited. This is when the image appears directly from exposure to light; for example albumen prints, gelatin printing out papers, blue prints, salted paper prints. These type of prints were made up until the early 1900s and tend to have a sepia tone.

“Developing out papers” became popular from the 1900s onwards. This process is less vulnerable to light. They have a true black and white or slightly cool tone. There was a significant crossover in the 1900-1910 with “developing out” techniques and albumen prints so a print cannot necessarily be assessed by its date.

Step 2 Care for the most vulnerable photographs first
Prints on display
• Restrict visible light – no direct sunlight, close the curtains, use low UV emitting lights.
• Put photographs in display case rather than on a bookshelf to filter the light.
• Preferably display digital copies and store originals.
• Do not write on the back of photographs with pen.
• Do not put pins through the prints.


Photo after treatment – no photoshopping

Storing
• Store in a cool, dry area.
• Treat in the same way as organic materials, like books and textiles.
• Silver gelatin emulsion is a perfect food source for mould. Once it is damaged, it becomes water soluble – once mould appears on a print, the staining in irreversible.

Enclosure
• Buy photographic archive storage containers that have passed the Photographic Activity Test.
• Images should be stored in individual enclosures to ensure mould do not spread or the chemicals in the image do not react against each other.
• It can be as simple as photo pockets in a ring binder, as long as the images are stored in good quality materials.

Step 3 Digitise and store images electronically
Scan and electronically store your most vulnerable images first to ensure there is always a copy. It is a good idea to archivally store the originals and exhibit the duplicate.

Scan
Scan prints at the highest resolution possible. When deciding on how large the file size should be, assess how much storage space is available and the end use. A preservation scan of a black and white image can be as large as 100MB while smaller institutions may save files at between 5MB and 20MB. If the end use is poster size for the backdrop of a display, the file will need to be closer to 100MB. If it will only ever be printed at 1:1 then a smaller size is fine. Scans of colour images will be three times as large.

Storing electronic files
Images should be saved in two to three sizes – thumbnails, low resolution and high resolution. Low resolution files are easier to handle. If there is limited storage capacity and time, just store the low (2MB) jpeg and high resolution TIFF files (5MB-100MB) and do not worry about the thumbnails.

Electronic files should be saved onto two hard drives that are synced so if one breaks, there is still another copy. Do not rely on one type of back-up.

A third copy should be kept remotely.

Options
• A data storage website. If the photo collection is small Flickr or Google’s Picasa offer free photo library storage. If the collection is comprehensive, a company like Jungledisk uses Amazon web services for remote backup. http://www.productwiki.com/jungledisk/
• Keep a second set of hard drives at an affiliated collecting institution or DVDs.
• CDs and DVDs need to be stored away from sunlight. They should only be used to move images from on eplace to another as they deteriorate over time. Archival DVDs are available.



Before treatment image photoshopped. It has only been photoshopped, not treated then photoshopped.

Step 4 Digitally restoring photographs
Photoshop is an excellent way to digitally restore images. There will always be a copy if the original deteriorates. Most community colleges offer Photoshop classes. Using Photoshop is an accessible way for the general public to preserve images when a photography conservator is not available.

The three basic tools are for contrast, colour correction and removing stains.
• Levels and curves manipulate the contrast
Go to “Image” > “Adjustment” > “Levels” or “Curves”
• Curves corrects colour and tone
Go to “Image” > “Adjustment” > “Curves”
• Cloning tool removes staining, mould or dust
In the toolbar. The icon looks like a rubber stamp.

Useful links
Preservation–related fact sheets
National Archives of Australia
Advice on how to “Secure, store and preserve”
Preserving photographs

Australian War Memorial
AWM curator Mel Hunt has written a blog post about how the multimedia department digitally preserved a photograph from Gallipoli by scanning and photoshopping it.
AWM conservation and preservation advice

The Institute of Conservation
How to care for photographs
How to conserve a photograph (download pdf)

Magazine article on the mistakes to avoid
Top Ten mistakes when preserving photographs

Photographic archive suppliers
Archival Survival
Preservation Australia
Zetta Florence

Training
Postgraduate Certificate in Arts (Photographic Conservation) can be taken as a short course rather than formal study. The course offers a format that suits community access.

The program emphasises the scientific and technical aspects of photographic materials deterioration and conservation. It draws on the combined expertise of staff of the Centre for Cultural Materials Conservation and internationally recognised leaders in the field. Cheryl Jackson teaches one of the four elements of the course – “Conservation of Photographs”.

For more information on photo preservation, email Cheryl.

6 Responses to “Tips+Tricks: Preserving photographs with Cheryl Jackson”

  1. Joy Suliman Says:

    Hi,

    Great article. Very useful and not too complex. Thanks Cheryl and the CAN team.

  2. Carolynne Bourne Says:

    Some questions which arise out of reading Cheryl’s article.

    I would be be most appreciative for specific information regarding:

    1. What is the appropriate/archival paper and gsm to print copies on
    to – manufacturer eg Epson?

    2. Is it better to print on to archival paper rather than that
    recommended by the printer manufacturer eg Epson, HP, etc?

    3. Which printer is the best, particularly related to inks eg
    permanency, colour, etc

    4. Taking that CDs and DVDs have a limited life, how often should the
    images be rescanned/resvaed on new discs?

    5. For printing off copies what is the recommended DPI?

    Many thanks.

  3. Cheryl Jackson Says:

    In answer to Caroline’s questions – It is important to use paper and ink that is designed for your printer. Manufacturers design their printers, papers and inks to work together for optimum colour rendition and permanence. If you have an Epson printer, you should use Epson papers and Epson inks. Pigment based inks tend to be more permanent than dye based inks, but you will need a printer designed to use pigment based inks. If possible you could have a dye based printer for everyday printing and a pigment printer for reproducing photographic images.

    The permanence of prints has been very thoroughly investigated by a testing facility in the USA – Wilhelm Imaging Research. See their web site http://www.wilhelm-research.com for many sets of testing results. You will be able to find the inks and papers they found to have the best permanence from their testing regime. Manufacturers use these results as a selling point for their own products.

    There are some art papers that have been tested for permanence on this web site as well as printer papers, if you don’t want the appearance of a modern resin coated paper.

    The life of a CD or DVD will be dependant on its quality of manufacture and its storage environment. Keep your master files on a hard drive (or two) and if you try to read one of the disks and errors appear, discard it and burn a new one.

    The recording layer on a burn-at-home disk (CD or DVD) is an organic dye. These are suseptible to deterioration as are all organic dyes. If the disk is exposed to heat or light the dyes may change causing errors to build up in the recording layer. The most stable dyes used in disk manufacture are phthalocyanine dyes. If the disk uses these more stable dyes, it will generally be written on the packaging as a selling feature. Gold reflecting layers are also more stable than silver and silver alloy layers.

    So a gold disk with a phthalocyanine dye layer is the most stable disk you will be able to buy, but you still should not be using disks as your only back up. They are a transport medium to get your files to another hard drive.

    Physical damage to the disk can cause instant loss of data – a deep scratch can ruin a disk. Disks should be stored in rigid cases away from light and heat sources.

    If your images have been scanned at the highest resolution you can manage, disks can simply be replaced by recording new disks from these files. The images shouldn’t need to be scanned all over again.

    There is no actual recommended DPI for printing. Any photo ready printer will print an image at a high enough resolution to make it look like a continuous tone “real” photograph. The quality of the print is more dependant on the quality of the scan from the original photo.

  4. Carolynne Bourne Says:

    Many thanks for your response Cheryl – most informative.

    We have a fellow who is undertaking his overseas travel program leaving Australia on the 6 September. He has meetings planned at the Wilhelm Research Institute.

    So as to make sure his questions to those he is meeting are as fulsome as possible – are there any areas in this field you believe are required which are not already covered in the curriculum in nationally accredited university or TAFE courses?

    I will forward your responses to him.

  5. Cheryl Jackson Says:

    Carolynne,
    There isn’t a lot of training in the technology and preservation of digital printing in Australia at the moment, so any information he can get will be of benefit. If he can get really up to date information on ink and paper manufacture, ie what’s on the market now, what are consumers actually buying. Also, more information on new dye based inks and how permanent they are getting, as most people use dye based printers at home, not pigment based ones.

    The other important area for furthur action in Australia is the use of sub-zero storage facilities. Preservation specialists know how important it is for colour images and B&W negs, but it can be hard to get the message across to the people with the money. If your Fellow could get some persuasive arguments for sub-zero storage, that would be great.

    Let me know how he gets on!

  6. Archives Outside » August 2009: Link roundup post Says:

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