Cal Poly

Preservation Basics

1. Climate

• The most vital action you can take to ensure the safety and longevity of a collection is to provide a stable cool, dark, and dry storage environment.
• Although different formats of records require slightly different environmental conditions, a compromise can be struck.
• Do not store in an attic, basement, or garage.

In General

• For paper based materials the temperature should range 60-65° F and relative humidity at 40-50%. Try to keep the temperature and RH stable and constant.
• Prevent mold and mildew. If RH over 65% for more than two days, or the airflow is stagnant, there is a risk of mold growth. Consistent relative humidity and temperature is very important!
• If you have dehumidifiers, air conditioners, and/or humidifiers, be careful not to turn systems off at night or during an off-season as rapid changes in climate and fluctuations can harm material.
• Avoid storing in direct sunlight! Keep storage areas dark. Use ultraviolet (UV) filters on florescent lights and keep windows shades or blinds closed.
• Isolate and inspect all incoming materials for signs of pest infestation.
• Guard materials from dust and other pollutants.

2. Storage

• Use Reputable Archival Supplies and Suppliers.
• Material should be placed in appropriate archival storage to protect them from light, dust, mishandling, pollutants, and temperature fluctuations.

In General

• Always use archival-quality storage materials acid-free paper, folders, and boxes
• Use Mylar, a stable polyester, or polypropylene or polyethylene

Housing

• Store documents upright (with support) in acid-free folders in acid-free boxes
• Match document size with its container
• Be careful not to overstuff folders or boxes
• Label folders and boxes as to contents and dates—this alleviates wear and tear when looking for an item
• Utilize appropriate storage containers for oversized materials (oversized storage boxes) or ephemera such as postcards or magazines (individual mylar enclosures)

Keep in mind when preparing material for storage

• Remove all fasteners, paper clips, rubber bands, and staples. Don't remove fasteners if doing so will cause additional damage
• Use Plastiklips™ to attach related documents, or an envelope to a letter
• Flatten documents (remove from envelopes if necessary)
• Using a soft brush, gently dust off dirt and dust
• Separate newspaper clippings. Photocopy onto acid-free paper and file with documents. If keeping original clipping, store in separate folder away from other documents
• Identify documents if necessary with a soft #2 pencil—on the back and along the margins.
• Separate fragile or torn documents. Place in protective sleeve and store in folders.

Warnings

• Do not laminate material as a method of preservation. Lamination can cause long-term damage.
• The use of tape or glue on materials will cause severe damage that may be irreversible.
• Avoid photo albums or scrapbooks that have a sticky backing.
• Digitizing your photographs as a long-term preservation option is not wise. It is unclear how long digital images will last, due to impermanence of storage formats.

3. Handling

• Additional information can be found in the book An Ounce of Preservation: A guide to the care of papers and photographs. By Craig A. Tuttle, Rainbow Books Inc., 1995

In General

• Use white cotton gloves to prevent smudges and oils from fingers that can cause staining on the paper/material. If handling material without gloves be sure hands are clean and free of lotion.
• Keep food, drink, and plants out of areas where records are stored or used. They can also attract pests.
• The use of adhesives, including post-it notes, pressure-sensitive tape, or glue, on historical materials can cause harsh damage.
• Prevent acidic items, such as newspaper clippings and faxes, from staining adjoining items. Place them in mylar or replace them with photocopies on acid-free paper.
• Do not lean or write on top of documents.
• Use pencils when working with collection to avoid possible damage from use of ink.
• If possible, store photographs flat, separating by size, format, and type. Store negatives and prints separately.
• Store photographs in an environment with lower humidity and temperature than for general paper collections.
• Handle photographs and negatives around the edges and wear cotton gloves.
• Place frequently handled photographs in sleeves made of plastic film (polypropylene, polyethylene, or polyester).
• Fragile materials need the extra support of rigid Mylar™, an archival quality polyester.
• Purchase storage enclosures from reputable vendors of archival products.
• Do not store material in glassine envelopes.
• Do not fold documents.

4. Preservation Copying

• Preservation copies are surrogate copies in place of fragile original material. They minimize handling for purposes such as exhibition, research, and duplication. Original material can be safely stored which protects them from damage, deterioration, loss, or theft.

In General

• Photocopy letters and documents.
• Make copy prints and negatives of photographs.
• Microfilm is also a viable preservation copy alternative.

5. Consult Professionals

• Conservation is a complex field with specialists in many areas, such as books and paper, photographs, fine arts and artifacts, surveys and preservation planning. Get professional advice before undertaking any kind of preservation project.
• Never attempt to repair a historic item or work of art yourself.
• Seek advice from a professionally trained conservator who specializes in the type of item you are concerned with.