QUOTE(RoseRodent @ Aug 16 2012, 12:29 PM)
My insurance company has sent me a bottle of Smartwater for my viola. I can't quite get over my horror at the idea they want me to put water on my instrument, but they are a specialist instrument insurer and there are many pictures of violins in the instructions. It doesn't say it would damage the varnish or anything, but then it says put it somewhere "inconspicuous" - not sure there is any such thing because I'll know where it is and I'll see it. Have people Smartwatered their stuff before? Where did you put it?
It is called SmartWater, but it is really a type of paint, which is almost invisible once applied. You would only apply a few drops, so it shouldn't be too visible. The paint is water borne, (I suspect it is a type of water borne acrylic), so it shouldn't harm your instrument.
SmartWater contains tiny flakes of mica or similar, which are etched with a unique number, visible only under a microscope. The paint also fluoresces (or lights up) when exposed to ultraviolet light so it is easily identified at a Police Station. The idea is that if the instrument is stolen, it can be positively identified if recovered. Fragments also tend to come off on a thief's hands, and are difficult to remove, and I am told that Police Stations routinely scan for SmartWater when suspects are 'booked in'.
The only reason I know so much about this is that we suffered a series of lead thefts from the roof of our local church over a period of a few weeks. The lead itself was valued at about 20,000 pounds, but the work to replace it cost more than 50,000 pounds! Thankfully most of this was replaced with a 'lead replacement material' which is not worth stealing; but I had the job of marking the edges of remaining lead with SmartWater so it could be positively identified at a scrap yard. Otherwise our insurance would have been null and void.
SmartWater is very expensive to buy, (I think at least 20 pounds a bottle), so your insurance company is clearly keen to protect your mutual investment. However, read the terms of your policy carefully, as many insurers now decline claims unless certain items are protectively marked with SmartWater. SmartWater has a website
and a help line number (0800 521 669) where they should be able to answer any questions.