SamuliSchielke
Well-fixed and washed black-and-white prints are considered to be fairly durable, but exactly how durable are they, and how can their lifespan be extended?
I’ve been told that prints on baryta paper are more durable than those on PE paper, and that their lifespan can be extended through gold, sulphur or selenium toner. What factors should be taken into account here? And what kind of timescales are we actually talking about? Decades? Centuries?
And while I’m at it, what about the durability of the negatives?
Best regards,
Samuli
Gast
Hello Samuli,
You can safely assume that a well-chosen silver gelatine print will last for decades, regardless of whether it’s PE or baryta paper. The days when PE was significantly less durable are probably over. On the other hand, there is simply no practical experience to draw on, only simulation tests (which apparently show positive results for modern PE).
With selenium or gold toning, you can expect a lifespan of around a hundred years.
Essentially, there are three risks:
Mechanical: this is probably the most significant. Here, PE papers might have an advantage.
Chemical (regarding the gelatin): if it gets damp, the gelatin can go mouldy or provide a breeding ground for other microorganisms.
Chemical (regarding the silver): Only toning helps here. Selenium or, better still, gold.
Take a look at photographs from the period before the First World War. They are primarily creased, torn or scratched, and may also be faded or mouldy.
If you want to rule out gelatin, you’ll need to opt for platinum or calotypes with gold toning.
As I said, preserving them mechanically for over 100 years is also a lot of work. But platinum on good paper should last as long as a Gutenberg Bible.
In principle, the same applies to negatives, although modern film bases, unlike celluloid, probably last almost forever.
Regards
Martin
Gast
Hello, Samuli!
Even without further treatment, a perfectly developed black-and-white photograph, when stored under favourable conditions, can last for generations. Toning or Sistan treatment can help to preserve it by protecting it from potentially harmful influences.
So, as you can see, several factors work together to ensure its longevity.
1.) The prerequisite is flawless processing with thorough but not excessive fixing and sufficient washing.
2.) The finished print must be protected from moisture, extreme temperature fluctuations, harmful gases (e.g. emitted from building materials or furniture) and mechanical damage.
3.) Certain toning processes (e.g. sulphur toning) convert the silver in the image into more stable compounds that are more resistant to environmental influences. Treatment with Sistan or comparable silver stabilisers is not a toning process, but it protects the image from degradation caused by residual thiosulphate (from the fixing process).
Best regards
Holger
Gast
Hey, what's happened there? When I typed it in, the text looked perfectly normal, without all that white space around it.
Holger
mau
Black-and-white film generally has a much longer shelf life than colour film.
As with almost all physical objects, the general rule is to store them in a cool, dry place (but not too dry).
Furthermore, baryta paper lasts longer than PE paper.
It goes without saying that processing is important, but that actually applies in general.
You should avoid storing PE and baryta together. New furniture that still has a strong odour is also unsuitable.
There are guidelines and standards for archival-quality processing (www.ehrleprint.de) and storage. The term PAT often comes up in this context. It is an American guideline that is widely used.
My personal experience:
A PE print, poorly fixed and/or water-damaged, begins to deteriorate after just a few weeks.
The same applies to baryta prints.
A well-processed PE print hanging on the wall will last several years, depending on the light intensity.
A well-processed baryta print will last for decades under the same conditions mentioned above.
Under archival conditions, the PE print should last several decades and the baryta print 100 years or more.
Furthermore, even when the print begins to change, the image information remains visible for a long time.
Life-extending toning is always advisable when the archival or display conditions are unclear or deviate significantly from the optimal conditions.
SamuliSchielke
First of all, thank you very much for your tips; they’ve been really helpful. However, there seem to be differing opinions on the archival durability of PE compared to baryta. Assuming all other factors are ideal: is PE really less durable than baryta, and if so, why? And if not, what has changed since the 1970s?
Gast
Everything essential has already been said, so I’ll just add a comment from my ‘practical’ experience with photography.
About thirty (?) years ago, I tested Oriental and Seagull papers, the first PE papers and classic baryta. These test prints are still stored today in a normal, dark cardboard box, under normal fluctuating “room conditions” (temperature between 17 and 24 degrees / humidity between 40 and 70 per cent). Neither the PE nor the baryta paper has visibly changed under these conditions. However, I expect that in twenty years’ time (i.e. after fifty years of storage), a difference will become apparent in favour of the baryta paper.
Twenty years ago, around 1985/86, I produced two comparative prints which, until two years ago, hung framed on the wall in a normal living room, subject to fluctuating temperatures and light exposure. Both papers were processed extremely carefully and correctly at the time.
Result: The image on the Guilleminot (G3) – baryta paper (unfortunately, this paper is no longer available) shows absolutely no changes. In contrast, the photograph on the Ilford PE paper has already changed significantly, showing ‘silver reflections’, brown spots and fading!
In plain language: the theoretical data regarding the durability of baryta and PE/RC papers is entirely accurate. So anyone wishing to own long-lasting prints (especially if they are frequently “hung on the wall”) should, or rather must, inevitably work with baryta paper. The extra work and effort are well worth it. Incidentally, I work exclusively on baryta paper, even for so-called “day-to-day jobs”; – but that probably has a great deal to do with “worldview” as well.
Gast
Sorry, I forgot to mention my name. Just so that no one gets annoyed again by an anonymous contributor from the world of ‘practical photography’.
Best regards,
Lothar van de Renne
Gast
Hi Lothar,
Do you happen to have any experience with the longevity of colour silver prints, such as heavy lith prints or gold/sulphur/selenium tonings tinted with colour? I’m referring to the colour quality.
Best regards,
Martin
Gast
Hi Max,
I can only comment on selenium (and Viradon/Agfa) toning, as I use these from time to time. I no longer use the latter, however. I would say that when I compare old baryta prints from the 1970s, which were often stacked (including in exhibitions under poor conditions), the life expectancy – without being able to give you specific figures in years – of selenium-toned prints is likely to be 10 to 20 per cent higher than that of untoned prints. Similar good results, though perhaps only up to 10 per cent, are likely to apply to Viradon/Agfa brown toning, as I have also found old prints using this to be in very good condition.
Agfa’s Sistan (silver stabiliser) is also said, like selenium, to produce very good archival stability. However, I have no practical experience with this myself.
So, if you want to produce a print that will last ‘forever’, then I would recommend baryta plus selenium toning!
P.S. … but who knows whether ‘forever’ is really something to strive for!?
See you soon
Lothar
