| |
| |
|
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 (amsden@btinternet.com) 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 http://www.ASAT.biz
MORE RESOURCES:
Science - Google News |
|
|
|
RELATED ARTICLES
NASA Budget VS Social Programs Balancing our quest for Space and its costs with the need of the people of our civilization is always at the top of the debate during NASA Budget hearings in the House and Senate. Some say that they think our primary planetary goal should be to colonize somewhere other than earth. Mars Surface Exploration and AFF As we study more and more about Mars we know there is life. Unfortunately in many regions of the planet it is not so evident. Pre-empt the Radiation or Die At West Point, in a speech, President George W. Bush shared the doctrine of pre-emption with his cadets that he articulated as a countermeasure to September 11 attacks. The Harmonic The HarmonicIn a good history book by a leading light in the field of history, I recall Michael Grant saying Pythagoras was 'weird'. This book is The Rise of the Greeks and he does almost admit he is not qualified to judge the great sage, which is more than many academics will allow. Cloaking the Postage Stamp Modern Aircraft Carrier By using a special coating on the deck of an aircraft carrier and a projector on the top of the tallest communications mast facing down, we could project the image of the ocean onto the deck like a giant IMAX theatre screen. Although this sounds like a daunting task, it isn't really. Down Scrolling Text to Find Patterns I believe a program can be written to scan text such as an email, story or article in Western Languages, which might indicate a pattern which maybe of valuable insight. By Down Scrolling Text, which we have all done, whether thinking about it or not, we will most likely Find Patterns Which Indicate Hostile Intentions, sadness, stress or vengefulness. Many Sci Fi writers have discussed Earthquake predictions Cal Tech along with the Universities in Japan are on the leading edge of this new technology and it is quickly becoming a reality. Soon we will know months in advance of an expected quake and the precise time maybe known hours or minutes before it actually comes. Astrophysics and Other Universe Sentient Life ASTROPHYSICS: - Many other entries will deal with knowledge from this truly amazing field of exploration founded in astrology and chaos science before the Ice Age. There is one question we'd like you to consider at this time. The Best and Worst of April's Weather If Johannes Kepler, the renowned 17th century astronomer and discoverer of the planetary laws of motion, could speak from the heavenlies, he might have a few words of wisdom to share with the National Weather Service. Although Kepler's name is not normally associated with meteorology, he was quite the weather forecaster in his day. UAV Acoustic Apparatus for Insect Swarming Stimulus, part two UAV Acoustic Apparatus for Insect Swarming Stimulus, part two; Using Locust swarms to attack our enemies using directional sound to guide them.These plagues and swarms seem to occur randomly, although we do know the migrations are due to over population in an area. Mars is not hollow; is it? Is Mars Hollow? We are pretty sure it is not, but no one can be certain however we might soon know. The reason such a question is asked is because of questions about the Earth and the time it takes for sound waves to travel through it. Stem Cells (The Truth) The much publicized stem cell research debate focusing on moral arguments is off target with the goal of real progress in the direction of human physiological benefits potential. No matter what side of this issue you come down on, practical considerations ultimately trump this emotionally clouded subject. 4D Mapping of Mars Will Find Life Let us discuss the mapping of Mars and some thoughts on the matter. We have mapped the Earth by using Satellites and have a complete GIS mapping with complete mineral deposits, underground oil areas, volcanic plumes and even huge natural water aquifers. Launching 400 UAVs from a Transport Plane How to launch hundreds of UAVs for an autonomous mission from a transport plane. As we watched the MOAB parachute bomb drop out of a C-130 onto the desert and above the tunnels below into Afghanistan, it left the world in awe. The Quantum Theory of Holy Languages The quantum theory of holy languages (QTHL) encompasses the three most influential fields of knowledge: science kabbalah, quantum physics and mathematic. Applications of this theory in alternative medicine by use existing human experience has many practical statements. Hydro-Mini Tsunami-Perpetual Wave Making Machine Let's describe this idea as a Self Generating a Tsunami-Perpetual Wave Pattern Making Machine to Derive Mini-Hydro Power Systems in Rivers.Hydro-Mini Tsunami-Perpetual Wave Making Machine. Three Types of Telescopes - What are the Advantages Refractors, Newtonian reflectors and Catadioptrics are the three main types of telescopes. All these different types have the same purpose, but each telescope design does it differently. Mystical Physicists INSPIRATIONAL COMMENTS:"There is a principle which is a bar against all information, which is proof against all arguments and which cannot fail to keep a man in everlasting ignorance - that principle is contempt prior to investigation. - Herbert Spencer"Albert Einstein - "We are seeking for the simplest possible scheme of thought that will bind together the observed facts. How Satellite TV Systems Originated What we know as satellite tv actually had its origins in the space race which began with the launching of the satellite Sputnik by the Russians in 1957. The first communication satellite was developed and launched by a consortium of business and government entities in 1963. Living In Arizona Boulders--Where Did They Come From? When most people think of building a secluded home, they think of tall trees and large bushes. But what about boulders?Granite Park, located in Prescott, Arizona, which is in the north central part of the state, is one such place filled with 1.
|
| home | site map | Xray Photography |
| © 2006 |
