Science Information

Paper - More than Meets the Eye

We are surrounded by so much paper and card that it is easy to forget just how complex it is. There are many varieties and grades of paper materials, and whilst it is fairly easy to spot the varieties, it is far more difficult to spot the grades.

It needs to be understood that most paper and card is manufactured for a specific purpose, so that whilst the corn-flake packet may look smart it is clearly not something destined for the archives. It is made to look good, but only needs a limited life span. It is also much cheaper to manufacture than high grade card.

Paper can be made from an almost endless variety of cellulose based material which will include many woods, cottons and grasses or which papyrus is an example and from where we get the word 'paper'. Many of these are very specialized, but the preponderance of paper making has been from soft wood and cotton or rags, with the bulk being wood based.

Paper from Wood.

In order to make wood into paper it needs to be broken down into fine strands. Firstly by powerful machinery and then boiled with strong alkalies such as caustic soda, until a fine pulp of cellulose fibres is produced. It is from this pulp that the final product is made, relying on the bonding together of the cellulose into layers. That, in a very small nutshell, is the essence of paper making from wood. However, the reality is rather more complicated. In order to give us our white paper and card the makers will add bleach and other materials such as china clay and additional chemicals.

An further problem with wood is that it contains a material that is not cellulose. Something called Lignin. This is essential for the tree since it holds the cellulose fibres together, but if it is incorporated into the manufactured paper it presents archivists with a problem. Lignin eventually breaks down and releases acid products into the paper. This will weaken the bond between the cellulose fibres and the paper will become brittle and look rather brown and careworn. We have all seen this in old newspapers and cheap paperback books. It has been estimated that most paper back books will have a life of not greater than fifty years. Not what we need for our archives.

Since the lignin can be removed from the paper pulp during manufacture the obvious question is 'why is it left in the paper?' The answer lies in the fact that lignin makes up a considerable part of the tree. By leaving the lignin in the pulp a papermaker can increase his paper yield from a tree to some 95%. Removing it means a yield of only 35%. It is clearly uneconomic to remove the lignin for many paper and card applications.

It also means, of course, that lignin free paper is going to be more expensive, but that is nevertheless what the archivist must look for in his supplies. There is no point whatsoever in carefully placing our valuable artifacts in paper or card that is going to hasten their demise. Acid is particularly harmful to photographic materials, causing them to fade and is some cases simply vanish!

So, how do we tell a piece of suitable paper or card from one that is unsuitable? You cannot do it by simply looking, and rather disappointingly, you cannot always rely on the label. 'Acid free' might be true inasmuch as a test on the paper may indicate that it is a neutral material at this time. But lignin can take years before it starts the inevitable process of breaking down, and in the right conditions it will speed up enormously.

Added to this, as I have indicated earlier, paper may also contain other materials added during manufacture such as bleach, china clay, chemical whiteners and size. This looks like a bleak picture, and it would be but for the fact that there are suppliers who will guarantee the material that they sell. If you want to be absolutely sure that you are storing in, or printing on, the correct material then this is probably the only way.

Incidentally, acids can migrate from material to material. Lining old shoe boxes with good quality acid free paper will do little to guard the contents. The acid will get there in the end.

Paper from Rag.

Paper is also commonly made from cotton and rag waste. This has the advantage of being lignin free, but because there is much less cotton and rag than trees, it also tends to be much more expensive than wood pulp paper. You will still need to purchase from a reliable source though, since even rag paper and card can contain undesirable additives.

A reliable source for quality rag papers is a recognised art stockist. Many water colour artists insist on using only fine quality rag paper and board.

The main lesson to learn from this information is that you cannot rely on purchasing archival materials from the high street. The only safe solution is to purchase from specialist suppliers. It may cost rather more, but in the end you will know that your important and valuable data and images have the best home possible.

Copyright Peter C. Amsden 2005

Peter C. Amsden ( has many years experience in photography, film and television. An Associate of both The Royal Photographic Society and of the British Institute of Professional Photographers. He had made a special study of conserving and archiving imaging media and is author of "Images for the Future". Runs consultancy and web design business, for more info. see

This RSS feed URL is deprecated, please update. New URLs can be found in the footers at


Are Personality Types In Science Cut Out For Contemporary Discourse?
Heck, I was even racially-harassed by scientists that disagreed with something I wrote about climate change. While that is awfully disheartening and frankly a bit pathetic, it is a topic for a different day, and the colleague that I spoke of can more ...

The Conversation AU

The science and art of reef restoration
The Conversation AU
Coral reefs around the world are in crisis. Under pressure from climate change, overfishing, pollution, introduced species and apathy, coral colonies and fish communities are steadily deteriorating. Coral cover in the Great Barrier reef has declined by ...

and more »

Science News

The brain may clean out Alzheimer's plaques during sleep
Science News
It would be easier to understand sleep deprivation if scientists had a better handle on sleep itself. The brain appears to use sleep to consolidate and process memories (SN: 6/11/16, p. 15) and to catalog thoughts from the day. But that can't be all ...


Star Trek technobabble: The science behind the science fiction
This post is part of Science of Sci-Fi, Mashable's ongoing series dissecting the science (or lack of science) in our favorite sci-fi movies, TV shows, and books. Star Wars is all action. You know, X-wings and lightsabers and fully armed and operational ...

NJ college freshmen just sent their science experiment to outer space
Most of us probably had one or two "out of this world" ideas win college. But, Daniel Schneider and Christina Tallone, two undergrads at Stockton University, actually got to send theirs to outer space. Along with carrying resupply materials to the ...


Science Figures Out Why the Tree Shrew Eats Red-hot Peppers
Now it has been observed that the ones known to science as Tupaia belangeri chinensis like to eat hot peppers, which don't grow in the trees where these nice animals hang. Genetic sequencing of the Tupaia tree shrew was enlightening. The Chinese ...

and more »

The Guardian

Venkatraman Ramakrishnan: 'Britain's reputation has been hurt'
The Guardian
Science by its nature has always been an international enterprise and in fact the more prestigious and high performing the lab or institute, the more international it is. It's very hard for the science community to see any advantages in Brexit. They ...

WIVB-TV News 4

Buffalo Museum of Science unveils new digital planetarium
WIVB-TV News 4
BUFFALO, N.Y. (WIVB) - The Buffalo Museum of Science is holding big Grand Opening celebrations this weekend as it welcomes the public back into the Kellogg Observatory for the first time since 1999, but that's not the only new draw there. The museum is ...

Science Magazine

Trump's pick to lead energy technology program puzzles observers
Science Magazine
“Based on his background it doesn't seem like a good fit to the job, and it is an important job,” says David Hart, a science policy expert at George Mason University in Arlington, Virginia, who has studied ARPA-E. Judging both a technology's technical ...

Michigan State turning old power plant into science center
Sacramento Bee (blog)
Michigan State University plans to turn an old power plant built in the 1940s into a place to learn science, technology, engineering and math. Groundbreaking is expected next month for the STEM Teaching and Learning Facility. MSU is spending nearly ...

Google News

home | site map | Xray Photography
© 2006