Many people want to sell their item immediately, without undergoing an independent appraisal. However, this can be a costly mistake. Without knowing its true market value, you risk selling it for much less than it's worth or advertising too high a price and never finding a buyer. Furthermore, buyers of collectible items seek to reduce risk before investing thousands of Brazilian Reais and tend to trust an opinion and certificate prepared by an independent expert much more than just the seller's word. This is why the preliminary appraisal is the first step: it allows for the analysis of the item's authenticity and value. When sufficient evidence is found, it can be followed by a certificate of authenticity, a document that reinforces buyer confidence and can facilitate a faster and higher-priced sale.

No. The preliminary evaluation analyzes the calligraphy of the signature or manuscript and the provenance of the piece. Based on these elements, Mathias Meyer assesses whether there is sufficient evidence to support its authenticity and indicates whether the item can be certified.

Yes. In some cases, the evidence is sufficient to conclude whether an item is authentic or not. In others, the available documentation does not allow for a definitive conclusion, and the result remains inconclusive.

No. For multi-signed items, such as a soccer jersey signed by a team, the Preliminary Assessment focuses on some of the signatures identified by the client and an analysis of the item as a whole, including the layout of the signatures, the medium, and the provenance. Identifying all signatures is not part of this service and, in most cases, is not necessary for Mathias Meyer to form his professional opinion.

Because it prevents you from investing in a certification when there aren't enough elements to support it. In some cases, preliminary assessment is also used to document the inauthenticity of an item and assist with refund requests.

The preliminary assessment is a professional opinion sent via WhatsApp to guide your decision. The certificate is a formal document, signed and stamped, prepared when there is sufficient evidence to document the item's authenticity.

The market value is estimated by comparing it with sales histories of identical or similar items sold by Glórias, by other specialists, or at auctions in Brazil, Europe, and the United States. For this purpose, we use professional databases of sales histories, such as Artprice, Drouot, Barnebys, and Invaluable, among others, and, when necessary, we also consult other market specialists. The estimate corresponds to the item's market value and does not consider potential negotiations with buyers, intermediary commissions, packaging and transportation costs, or taxes, which may vary depending on the chosen sales method.

No. The opinion on authenticity is always Mathias Meyer's, based on graphic comparison and provenance analysis. Artificial intelligence can only be used as a support tool for contextual research or text review.

Mathias Meyer has been working in the autograph and historical documents market since 2010. He is a member of the International League of Antiquarian Booksellers (ILAB) and has analyzed thousands of autographs, manuscripts, and collectibles for collectors, lawyers, auction houses, institutions, and sellers in Brazil and abroad.

Yes. Some appraised items may subsequently be sold through direct sale or auction. However, only pieces approved in the preliminary appraisal and certified are offered to our customers, ensuring greater transparency and security.

Because its objective is to answer the customer's main questions: whether the item can be authenticated, how much it is worth, and if it is worth certifying or selling. Furthermore, we do not disclose technical details that could facilitate the improvement of counterfeits.

No. Each preliminary assessment is conducted individually and requires a complete analysis of the signature, provenance, and available documentation.

We specialize in autographs and historical documents, including letters, manuscripts, dedications, photographs, books, signed works, shirts, balls, and other collectible items. For other categories, such as antique books, jewelry, watches, luxury handbags, and classic cars, we rely on partner specialists in Brazil and abroad.

Via WhatsApp or email, send clear photos of the item (front, back, sides, and important details), inform the name of the signatory author, if known, and share all available information about its provenance: where, when, for whom, and in what context it was obtained.

The Preliminary Assessment represents the professional opinion of Mathias Meyer, based on his experience and analysis methodology. If you disagree with the conclusion, we recommend requesting an assessment from another market-recognized expert to obtain a second opinion. In any case, the fee for the Preliminary Assessment is non-refundable.

The preliminary assessment is sent within 24 hours of receiving the photos and the necessary information for the analysis.