ENCAPSULATION

Some items which require protection, but whose value or structure prohibits the use of invasive conservation techniques, may be encapsulated. Encapsulation involves the sealing of individual sheets of paper between sheets of clear polyester. It is the standard treatment for maps, manuscript material, prints, and fragile or brittle single sheets.

SCOPE

This treatment is generally limited to Special Collections items.

EQUIPMENT

Welder

At the University of Florida Libraries we use a Minter Ultrasonic Welder, model OT, purchased in 1987.

The welder should be cleaned and recalibrated monthly, or whenever a large run of material needs to be done, and/or the machine has been unused for a while.

Polyester Sheets

There are two types of polyester recommended for conservation. They came in a variety of thicknesses. with 2-5 mil being the most frequently used. They are:

Melinex 516
Dupont Mylar Type D.

EVALUATION

The candidates for encapsulation should be printed, typed or manuscript material. Artwork may not consist of friable media such as charcoal, chalk or pastel. Such media is loosened by the electrostatic charge of the polyester. Material should not be overly thick or adhered to board or have a rough, three dimensional surface.

Several things have to be taken into account before encapsulation. They include:

Single or multiple sheets,
If multiple, are they all the same size,
How will the completed items be housed.

Will they be:

Boxed, enveloped or pam bound ?
Replaced into the original volume ?
Bound ?
Stored loose in map drawer ?
Other.

PREPARATION

Examine the item to be encapsulated for any damage and assess any treatment that needs to be perfomed before encapsulation. Treatments may include but are not limited to:

Removal of old tape repairs,
Surface cleaning,
Repair of tears,
Deacidification,
Relaxation and/or flattening of folds or wrinkles
Washing

Any treatments needed are performed on the item. It is not usually necessary to repair all small tears. The edges of the paper is held together by static after encapsulation. Usually the less that is done to the original the better.

PROCEDURES

Item is measured and appropriate sized polyester is chosen, or cut from the roll. Thickness of the ployester is generally determined by the following criteria;

Up to 80 square inches (8 x 10)...2 mil front and back
80 - 240 square inches ( aprox. 14 x 17)......2 mil front, 3 mil back
240 square inches.....3 mil front, 5 mil back

Generally the heavier sheet of polyester is on the back for support

SINGLE SHEET, REPLACED IN ORIGINAL BINDING..

Occasionally an original illustration, plate or photograph needs to be encapsulated and placed in the rebound or photocopied volume. The steps are as follows:

Examine and treat item.
Cut mylar leaving necessary left side binding margin.
Run foredge seam,

Run opposite seam,
Run top and bottom seam.

Trim edges as necessary to fit the binding and pam bind into volume

SINGLE SHEET - STAND ALONE.

Single stand alone items may be letters, prints, photographs, maps or other single items. Small items such as letters will probably be housed in an envelope pamphlet binder. Large items such as large maps will be housed flat in a map drawer, so they do not need added housing.

Examine and treat item.
Cut mylar leaving minimum one half inch on three sides, two inches on remaining side.
Run foredge seam,
Run opposite seam,
Run top and bottom seams.
Insert and seal in security/ID strip.

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