Blue Wool Standard

Blue Scales (Textile Fading Cards)

Description

[International Standards Organization] A standard developed to characterize lightfastness of materials. The Blue Wool Standard consists of a card that contains eight sections of blue-dyed wool cloth, each with a different lightfastness. The dyes fade at a known rate. Each section requires about twice as much light exposure as the preceding section in order to fade to the same degree. Section ISO 1 is the most fugitive and ISO 8 the most stable. In the absence of ultraviolet light, it takes approximately 400,000 lux hours to cause noticeable fading for the ISO 1 level and 900 million lux hours for the ISO 8 level (Michalski 1990).

Synonyms and Related Terms

Blue Wool Fade Card; ISO Standard R 105; British Standard BS 1006; fading card; norme ISO laine bleue (Fr.)

Additional Information

° S. Michalski, "Time's Effects on Paintings" in Shared Responsibilities. National Gallery of Canada, Ottawa, 1990. p.39-53.

° R.L.Feller, R.Johnston-Feller, "Use of the International Standards Organization's Blue Wool Standards for Exposure to Light" AIC Preprints of Papers presented at the 7th Annual Meeting, Toronto, Canada, 1979.

° R. Feller, "Standards in the evaluation of thermoplastic resin" in ICOM committee for Conservation preprints, 5th Triennial meeting, Zagreb. Paris:ICOM, 1978.

Sources Checked for Data in Record

• External source or communication Comment: A.Derbiyshire J.Ashley-Smith "A Propsed Practical Lighting Policy for Works of Art on Paper at the V&A" ICOM preprint, Lyon, France, 1999. p.38-41.

• Conservation Support Systems, Catalog, 1997