The sources (springs) of the authenticity .Avant any transaction of purchase or sale of a work of art, it is essential to give evidence of the authenticity with certainty. For that purpose, various document types can be produced. So, experts’ certificates of authenticity or invoices of companies(societies) of sales are not the only documents to have a value on the market. He(it) exists, for certain artists and certain objects, other confirming ways(means) or not the authenticity of the good(property). The catalog reasoned by an artist is a work realized by a specialist – conservative (curator), academic, scholar, heir of artist or expert-, who has authority to reproduce all the works of the concerned artist. The seriousness of the research work makes that the presence of a work in a reasoned catalog is most of the time a security of authenticity. The certificates of introduction in a reasoned catalog are not necessarily “certificates of authenticity”, but often have equivalent value in the eyes of the market. Indeed, a reasoned catalog or a complementary(additional) volume sometimes puts years to be drafted. To confirm that the work will appear in the future work, the writer supplies to the owner a document which guarantees that the work will be mentioned well there – and thus recognized as authentic by the market. The intervention of the curators is more trivial. Articles 4 and 8 of the decree of 1990 organizing the status of the bodies of the conservatives(curators) indeed plans that ” The members of these bodies cannot be engaged(surrender) directly or indirectly in the business(trade) or in the expertise of oeuvres of art and collector’s items “. In France, the curators are state employees, who can free (deliver) on no account from certificate of authenticity. So, the private individual who would present an object to a conservative (curator) will receive from him/her only an evasive answer. On the other hand, a conservative (curator) can draft a reasoned catalog either be downward of an artist. In a private capacity(personally), he can thus free(deliver) a certificate of introduction or authenticity. Furthermore, in certain cases, the simple point of view of a curator is essential for a gratitude (recognition) on the market: it is the case, for example, when this one is in charge of the museum dedicated to the artist. There are thus indirect exceptions in the principle of nonintervention of the conservatives(curators) The legal successors of artists – beneficiaries of the moral and patrimonial rights, susceptible to seize works within the framework of the procedure of confiscation of infringing goods – often appropriate the power to recognize the authenticity. So it is advisable to be all eyes and to make validate by the legal successors the paternity of the concerned work. Artists’ committees, often set up by the legal successors, also have authority to establish the authenticity of the works. A committee can be created for an artist fallen in the public domain. In this hypothesis, he(it) gathers(collects) personalities being interested in the work and realizing research works on the latter. Even there, these committees free(deliver) certificates which it is advisable to obtain to see recognizing a work. The experts as for them supply real certificates of authenticity. The specialist of an artist or a type (chap) of piece of furniture is often considered as one of the references in his field of expertise. Certificates supplied by these experts make – generally – authority on the market and are freed(delivered) during auctions or during private sales. The general practitioner deals with all the domains of the market; he can free (deliver) a certificate of authenticity and engage his responsibility, but, if there is a particularly competent expert for a precise work, only the opinion(notice) of the latter will then be retained. The auctioneer also has to, by virtue of the decree of 1981, produce documents giving evidence of the degree of authenticity of the sold good (property). He(it) does not supply strictly speaking a certificate of authenticity, but he(it) is held responsible for descriptions mentioned in the catalogs of sales, in the slips or the reports(fines) of sale