I did a mural ( one of two ) for a high class decorator's showroom near St Tropez, of the bay of St Tropez, made to look as if it was done by someone 2 centuries or so before and aged accordingly, the aging was all "trompe l'oeil". I heard later that he was passing it off as "he had painted it", and had placed a vase so as to hide what was my descreetly placed signature. I then heard that when challenged about his claim by a friend of mine who knew it was my work, his reply was that he would paint out my signature.In France this is illegal, so I had a lawyer write to tell him so, and that if he persisted in this "passing off" I would sue.Apparently his lawyers must have told him that the law was on my side.I subsequently heard that he was telling people that I had painted it, but that I was now dead.
Similar thing happened a few years later with our custom painting and murals, decors business, we had hired a sales rep, ( unemployed guy who showed up one day looking for work , who we felt sorry for ) on a commission basis, who we gave a "press book" ( french term for book of sample photos of what you have done ) ..One day I got an extremely irate phone call from someone about really shoddy work that had been delivered to them.
I had never dealt with them and said so. They asked me to visit, which I did.Turned out that our "rep" had been telling people that it was he who had done all the work in the press book. He had taken an order for custom work, delivered it, been paid cash by the customer's wife and left.It was indeed incredibly badly done.Further investigation found that he had used my press book to get various grants to set up his new business claiming it was what he could do.He had claimed around €10000.oo this way.I went to see the people who had authorised these grants and asked them why someone called Stephan, had been able to grants based on showing a few hundred photos of work which all had visible signatures with Mike on them. The reply.."not my job to verify who did the work".. His dossier was complete, so all was in order..They would not be asking foir the govt money to be given back*
My wife phoned the guy and told him to bring back the press book, or I would visit him, and deal with him.
He brought it back when he was sure I was not around..no point sueing him, he had no money..he had a wife and kid, not their fault.I saw him once, from a distance, he saw me, then he hit the car in front of him as he tried to get away.
* If they had asked for it to be repaid, they would no doubt had to explain why they did not notice that the work shown to justify the grants bore a name other than that of the supposed artist.
This is a reason to mark one's work, it prevents passing off, or at least makes it more difficult, and more likely to come to light.