Collecting old letters and documents is an increasingly popular pastime. The documents and letters contain historical details missing from the official history books and provide an immedicate link to the past. Many documents also provide a valuable source of family history.
So you have your letter newly acquired from an auction, car boot or grannies cupboard, how do you ensure it is still there when you are a grandparent?
All paper is fundamentally made of cellulose in the form of finely broken down plant fibres. In its purest form, cellulose is extremely durable, but additives can cause deterioration, usually through acid degradation, which weakens the fibres. The media used on the paper my be unstable too: pigments can fade or darken, some inks bleed or corrode the paper. Even the best rag paper can be subject to the same problems as the cheapest wood based paper. Vellum, used mainly for legal documents, is longer lasting but can still suffer from problems with the ink, indeed, the ink used on old legal vellums was intended to be scrapped away so that the vellum could be reused or corrected.
Causes of Damage
Exposure to light, poor quality mounting (including the use of unsuitable framing materials such as cardboard for backing), inappropriate handling, display and storage are just some of the causes. Amateur restoration techniques (stamp hinges and cellotape spring to mind) are also a cause of damage.
Many documents have been damaged by atmospheric pollutants such as sulphur and soot from open fires, candles and gas lights, these will cause the destruction of the paper.
Rodents are also a problem. If a mouse can get to your documents it has no scruples about using a two hundred year old letter for it's nest.
Last but not least are insects and mould. These will only affect the paper where the conditions are right, e.g. high humidity and temperature. It is disheartening to see a fine document that the slugs have had a lunch off of.
Signs of Damage
Insect and vermin damage is obvious, but most people will be familiar with the brown spots called foxing. The brown spots are caused by bacteria and mould which grows on acidic paper when the humidity is high. It can also occur on metallic particles from the paper making process become embedded in the fibres.
Where paper pressed against cardboard contiaing unpurified woodpulp it will turn brown and brittle. This happens mostly where a document has been mounted with cardboard as a backing.
Glue or adhesive tapes used to mount or repair documents will cause yellow stains on paper. Self adhesive tapes can be very damaging as the glue creeps into the paper and it becomes impossible to remove.
Too much light causes fading.
Storage and display
Paper documents should be stored in a primary archival enclosure such as a folder or envelope. The primary enclosure should then be stored in an archival box. All of these enclosures should be ph neutral/acid free. There are a number of companies on the web that can supply such items.The primary enclosure can be any of the following depending on individual preferences.
Examples are paper enclosures such as file folders, envelopes; polyester enclosures such as binder pages, envelopes, folders; polypropylene enclosures such as envelopes, sleeves and binder pages.
When more than one document page is stored in the same primary enclosure it is helpful to place archival sheets between the document pages. I use acid free tissue paper. It is very helpful to spray poor quality paper documents with a deacidification solution before storage. Newspapers will benefit greatly from this treatment.
Folded letters and documents should be stored unfolded so as to not put a strain on the folded edge.
After documents are placed in primary enclosures, they should be placed in an archival storage box that is a suitable size to house the primary enclosures. Documents stored in the polyester or polypropylene binder pages can be housed in an archival binder album.
Do not confuse poly pockets, which you can buy by the hundred for a low price, with archival neutral ph polyester or polypropylene pockets which are listed at around 35 to 45p each for A4. The cheap poly pockets are still active and give off chemicals which will attack your document.
Do not handle documents with bare hands, always wear cotton gloves.
If you decide to frame your documents for display, protect them from daylight, particularly avoid south facing light. Try not to hang them directly against the interior of the outside wall of a building. The comparatively low temperature can cause condensation and the dreaded mould. On the otherhand, a radiator or spotlight will dry the air out. If possible get a good scan and produce a high quality colour print.
When choosing a suitable storage area avoid damp cellars and uninsulated attics.
If you decide to get a document framed ensure that the framer can answer the following questions
- Are they using UV protected glass?
- Will the front and back of the mount be of solid core 100% cotton board (museum board), which is the best quality, or purified woodpulp board (known as conservation board)?
- If there is no window or overmount, will the glazing material be spaced away from the document surface?
- Will the document be attached using acid free paper hinges and a water soluble adhesive?
- Will there be an isolating layer between the backmount and frame backboard?
- Will the frame have enough depth to accommodate the mount, backboard, etc and the strengh to take hanging fittings secured to the frame and not the backboard.
If you are not confident that the framer can meet these standards contact the Institute of Paper Conservators to find the address of one who can.