UMCA Technical Leaflet

SELECTION OF FABRIC FOR LINING THE INTERIOR OF EXHIBIT CASES

Several factors determine a fabric's safety for use as a lining material.  Certain fibers, such as silk, are by nature acidic and should not come in direct contact with objects that are vulnerable to acid.  Other fibers may emit harmful volatiles, such as sulfur compounds.  Wool fabrics and felts containing wool are an example.  These should be avoided.  In most instances the safest fiber choice is probably cotton or linen because these fibers are by nature chemically stable.  An undyed and unsized cotton or linen fabric is best.  All fabrics, regardless of fiber content, should be washed prior to use to remove any potentially harmful sizing or finishing compounds from the textile.

The use of dyed fabrics for lining a case is more problematic.  Ideally, only undyed fabrics should be used in the enclosed environment of an exhibit case, and it should be recognized that using dyed fabrics is a compromise in terms of preservation.  An alternative to using a dyed fabric is using an undyed linen.  Linen comes in a variety of natural shades that range from light to dark and may provide the appearance required.  Also, linen can be woven in a variety of weaves from fine to heavily textured that look well with many different types of objects.

A line of naturally shaded cottons is also commercially available through Vreseis Limited, P.O. Box 87, Wickenburg, AZ 85358.  Colors range from beige to brown to green.  Woven fabrics and jersey knits are available.

If a dyed fabric must be used, the fabric needs to be tested carefully.  Colorfastness is a concern because permanent damage can occur if the dye transfers or bleeds onto an object due to contact with high relative humidity or water.  To test for colorfastness, begin by washing the fabric repeatedly until no color appears in the rinse.  Then test the fastness of the dye by spaying the fabric with water and weighting the fabric against a clean white blotter.  If no color is transferred to the blotter, the fabric is probably safe to use.  As an added precaution, the displayed object should not be placed in direct contact with the fabric.  Place an inert material, such as polyester film (Mylar), spun-bonded polyethylene sheeting (Tyvek), or archival board, beneath each object.

An additional concern is that dyes may contain volatiles harmful to objects in a closed case, particularly a tightly-gasketted one.  The fabric should be tested with metal coupons to determine if volatiles are being emitted.  Directions for conducting this test are available from the Upper Midwest Conservation Association on request.

Lightfastness can also be an issue with some fabrics.  There are no simple and quick tests for this.  If lightfastness is a concern, select a fabric that is intended for use as a furnishing fabric rather than as a clothing fabric.  Furnishing fabrics, however, tend to be less colorfast.

Finally, the method used to attach the fabric to the case should be carefully considered.  Although sewing is usually the safest option, rust-proof staples, nails, or tacks can be employed.  The use of most adhesives is questionable.  Only stable, inert ones should be considered.

If you have questions when selecting a fabric, contact the Upper Midwest Conservation Association for assistance.

Sherelyn Ogden, Director of Field Services,
Upper Midwest Conservation Association,
May, 1998