UV Lights
These lights are valuable tools in detecting restoration on ancient objects. There is nothing necessarily wrong with restoration. Indeed, for certain kinds of fragile works, it is to be expected. But a careful inspection should always be made before acquisition of any piece to determine if it has been restored, and if so, how much and how well done. An essential tool in performing these tasks is an ultraviolet lamp, many of which come with built-in magnifier lens. Every serious collector should have one and know how to use it.
Ultraviolet lamps are commonly called “black lights,” and they are modestly priced in different sizes from 4-watts to 100-watts. They emit long wave radiation and produce little visible light, mainly violet because that is the color of the shortest wavelength of visible light. UV lamps are used for what is called “fluorescence analysis” because everything responds differently to ultraviolet light: some objects become illuminated, literally glowing, while others remain muted or even turn “dark.” To the naked eye, a ceramic vessel may appear to have an unblemished surface, but subjecting the piece to ultraviolet light may reveal a patch of slight discoloration. Upon its discovery, analysis is necessary to determine what lies behind the discoloration, for example, a crack has been sealed or patched. On an effigy vessel, of say a deer, ears that glow differently would suggest that one is a complete replacement. Generally, what one looks for are discrepancies and inconsistencies in the coloration of surfaces under ultraviolet light.
Many materials worked by Pre-Columbian cultures can be gainfully studied with an ultraviolet lamp: weaving, stone, bone, feather, wood and shell, but UV lights are particularly useful for studying ancient ceramics. Once when examining a textile made of feathers, I observed a number of them standing out, of being more florescent under the ultraviolet lamp. They proved to be dyed chicken feathers that had been surreptitiously added to fill damaged areas. Under ultraviolet light, stone objects may reveal areas that have been broken and re-glued or where chips have been filled with bonding material. On ceramics, newly added paint responds differently to ultraviolet light than paint from ancient times. It is important to first observe with the naked eye whether the vessel has been waxed or varnished, as these substances can prevent UV light from penetrating the surface.
Good restoration work enhances the appeal of an object and does not compromise the integrity of the artifact. But it is always best to know the extent of the restoration work. One should not pay a premium for the reputed pristine condition of an artifact when, in fact, the piece has been extensively restored. Also, some restoration is shoddily done or is not in keeping with the original intention of the ancient artisan. Ultraviolet lamps are not useful for detecting outright forgeries or when objects have been given a completely new surface, such as the addition of a coat of varnish. These lights are best suited for detecting restoration work. We carry a full line of Spectroline UV lamps, each of which comes with a warranty. They are well made and properly calibrated, and are thus used by many museums.
David Bernstein Fine Arts, All Rights Reserved. C Copyright 2008