B (183)

52

B+W

10ºF increase in temperature’. Excessive heat

can cause colours to fade, dyes to degrade

and the lighter areas of prints to turn yellow.

When heat is combined with high humidity,

mould and mildew start to thrive. Both

of these organisms can scar the surface of

prints, causing serious damage to emulsions.

Extreme low humidity, on the other hand,

can cause materials to become brittle, while

print edges curl and emulsions flake.

O

bviously, neither of these

extremes is ideal and fluctuating

between the two can cause a

whole new set of problems.

Ideally, you should store your photographs

at a steady temperature (conservationists

suggest 40ºF or less for contemporary colour

work and 70ºF or less for most other pieces)

and at a relative humidity of 30-40%. But

most of us don’t have the space, money or

desire to invest in expensive climate control

equipment, so the best course of action is

to keep your collection in a cool, dark, dry



Conservationist Susie Clark removing later

framing materials from a Niépce frame.

This work was part of a Getty Conservation

Institute and National Media Museum

collaborative research project.

© Dusan Stulik

© Dusan Stulik

Rufus Anson, Portrait of a young woman, c.1855.

A typical daguerreotype in its case.

Rf A P t it f 1855

© Royal Photographic Society Collection at NMeM/SSPL

place. In short, avoid basements, attics and

garages, and keep pictures off the floor

(insects such as silverfish and cockroaches

enjoy the taste of gelatin and albumen,

so don’t make an easy meal for them), and

don’t hang anything you love in a bathroom

or above a radiator.

Finally, we come to the issue of poor

storage. You’d be forgiven for thinking that

any kind of storage is better than none but,

sadly, this just isn’t the case. Choosing the

wrong kind of mount, glass, sleeve, frame or

envelope can have a devastating impact on

your collection. Over time cheap adhesives

can exude chemicals, rubber bands, paper

clips and staples can leave harmful residues

and glassine paper bags can become acidic.

Even if an item is labelled ‘archival’ it is

imperative that you find out exactly what

the manufacturer means by this (the term

usually describes material with a neutral or

slightly alkaline pH, but some retailers use

it a little too freely). If you are in doubt, ask

where a product has come from and how it

was produced.

Most photographic materials can be

stored in paper or plastic envelopes, folders

or sleeves. Ideally these items should pass

a Photographic Activity Test (PAT) before

being considered suitable. The test assesses

the likelihood of chemical interactions

between storage materials and emulsions

(see imagepermanenceinstitute.org). If an

item does not state it has passed a PAT, don’t

automatically disregard it, because it might

never have been tested. Only you can decide

how stringent you want to be.

A

s a rule, paper enclosures should

be acid and lignin free and can

be alkaline buffered (which

neutralises acid) or un-buffered.

Whether you choose buffered or unbuffered

paper will depend on the end use – modern

colour work should not be stored in buffered

enclosures, for example. Plastic enclosures

can be made of polyester, polyethylene,

or polypropylene (although plastic must

not be used for glass plates, nitrate or

acetate-based negatives). Try to avoid

polyvinylchloride (PVC) where possible,

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