IF YOU WANT TO BUY important paintings from 100 to 600 years old, you had better learn the proper use of ultraviolet lights in analyzing their condition. Virtually all major auction houses, offer clients the critical ability to view paintings under UV lighting during the presale exhibits. ARC Chairman, Fred Ross managed to take these four excellent snapshots of the professional in-painting on the face and hands of Mignon by William Bouguereau.
Two of the prominent practitioners of the Modernist Century in art, proudly exhibited Bouguereau paintings in their personal collections: Salvador Dali, and Andy Warhol, of which this painting, Mignon was sold with his Sotheby’s estate sale roughly a decade ago.
Basically the paint from the original work glows differently than newer paint which glows a deep dark nearly blackish purple. However, the novice with this UV knowledge must resist the temptation to be over confident, since at times the glow from these lights can be misinterpreted. Let me explain!
I once had a Guillaume Seignac painting which had been partially cleaned on only the hands and face of the figure. The green, wet-behind-the-ears youngest member of the 19th century department at Christie’s at that time, took one look and decisively declared that the entire face and both hands had been repainted making the painting nearly worthless in her opinion. Since this was over 20 years ago, and I was not well known there yet, I could not get any higher-up to come out and "manage" the situation. I simply headed across town to Sotheby’s where the then second in command of 19th Century European Paintings instantly read it right, (only the hands and face had been cleaned on an otherwise filthy painting). He accepted the consignment and the painting sold for $8,000 the correct price for 12 x 18 inch Seignac in the early 1980’s. It’s no wonder that the gal at Christie’s found another field to occupy her time, and the fellow at Sotheby's was recently promoted from one of the top departmental jobs to an even more important executive position.
Ultraviolet lights are tools of analysis, and like all tools, experience pays off, at times in a big way. Sometimes over-zealous restorers or inexperienced ones can find themselves having difficulty in painting an important area - like the cheek on the face of an important portrait. What they sometimes do then, is to repaint the entire cheek, thus lowering the value big-time for potential and sophisticated buyers who know to look under the black light. If you guess right in such a situation, you may find yourself making an offer far below estimate on a painting that was eschewed by other collectors not wanting an over restored work in their collections. If you’ve guessed right, all that paint will come off and the original work will bounce back with all it’s glory and beauty, perhaps being worth twice or even four times what you paid for it. If you guess wrong, it’s worth even less than you paid for it... but hopefully you can write it off on the taxes with next year's superlative earnings. Below is an example:
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