Find out if your item is authentic, how much it's worth, and what to do with it
Find out if your item is authentic, how much it's worth, and what to do with it
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Preliminary Assessment
You send photos, information, and relevant data about your item and receive a professional assessment via WhatsApp, based on the material provided. The Preliminary Assessment is a paid professional service. We do not offer free professional opinions on the authenticity or value of items before the preliminary assessment is contracted.
You receive
✔ Professional opinion on the item's authenticity
✔ Estimated market value of the item
✔ Guidance on what to do with the item: preserve and enhance value, sell, or consider other alternatives
✔ Information on the possibility of certification and sale
How it works
1. Send photos and provenance information for the item.
2. Analysis is completed within 24 hours.
3. Receive your professional opinion via WhatsApp.
IMPORTANT | Everything is done 100% remotely: you don't need to send your item by mail.
Prices
✔ R$ 90 per item, deducted from the certification price if it is carried out.
✔ For unsigned or high-value items, collections, or specific projects, please contact us for a custom quote.
Important
The Preliminary Assessment is not a quote for the sale of the item nor a certificate of authenticity. It is an initial professional analysis that allows for determining probable authenticity, estimating market value, and guiding on the next steps.

Frequently asked questions
May I send photos to get an opinion before hiring the appraisal?
No. Both authenticity analysis and value estimation are professional paid services. To receive a professional opinion on your item, you must commission a Preliminary Appraisal.
If I just want to sell my item, why do I need a preliminary appraisal and, in some cases, a certificate?
Because without knowing the market value and probable authenticity of the item, you risk selling it for less than it's worth or listing it at a price that makes it difficult to sell.
Furthermore, buyers of collectible items seek to reduce risk before investing and tend to trust an appraisal more, and when recommended, a certification carried out by an independent expert.
The Preliminary Appraisal is therefore the first step: it allows for an analysis of authenticity, an estimation of market value, and guidance on the best strategy for the item. When there are sufficient elements, it may be followed by a certification.
Why is the Preliminary Assessment mandatory before certification?
Because it allows for a preliminary check to see if there are sufficient elements to support a certification, and prevents the client from investing in a certification that is not recommended.
What is the difference between the Preliminary Assessment and the certificate?
A Preliminary Appraisal is an initial professional analysis, conducted remotely based on photos, information, and provenance elements provided by the client. Its purpose is to assess probable authenticity, estimate market value, and guide on next steps.
The certificate is a formal document intended to professionally document the item's authenticity, when there are sufficient elements to support it.
Does the Preliminary Assessment ensure the item is authentic?
No. The appraisal does not guarantee authenticity. Among other elements, it analyzes the handwriting of the signature or manuscript and the provenance of the piece to determine if there is sufficient evidence to support its authenticity and indicate if the item can be certified.
Are there cases where it's not possible to reach a conclusion about authenticity?
Yes. In some cases, the evidence allows for a conclusion that an item is authentic or inauthentic. In others, the available information does not allow for a sufficiently confident conclusion, and the result remains inconclusive.
Will all subscriptions for my item be analyzed?
Not necessarily. For items with many signatures, such as a soccer jersey signed by a team, the analysis may focus on a few representative signatures and the item as a whole, including the arrangement of the signatures, the medium, and the provenance.
The individual identification and analysis of all signatures are not necessarily part of the Preliminary Assessment.
How does Mathias Meyer determine an item's market value?
Market value is estimated primarily by comparing it with historical sales of identical or similar items sold in Brazil and abroad.
The item's strengths and weaknesses are also considered. The estimate corresponds to the market value and does not include any negotiations with buyers, intermediary commissions, packaging and transport costs, or taxes, which vary according to the chosen method of sale.
Do you use artificial intelligence?
Not for authenticity determination. The professional opinion is that of Mathias Meyer and is based on graphic comparison, provenance analysis, and other relevant elements.
Artificial intelligence tools may eventually be used to support contextual research or text review, but they do not replace professional analysis.
What is Mathias Meyer's experience?
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.
Do you buy or sell the items you appraise?
Some appraised items may subsequently be sold through direct sale or auction. However, only items approved in the Preliminary Appraisal and certified are offered to our clients or partners, ensuring greater transparency and security.
Why doesn't the Preliminary Assessment present all the details of the analysis?
Because its objective is to answer the client's main questions: what is the likely authenticity of the item, how much it is worth, and what are the best options for it.
Furthermore, some technical details of the methodology are not disclosed to avoid facilitating the improvement of counterfeits.
Is there a discount for multiple items?
The Preliminary Assessment is carried out individually and requires a specific analysis of each item. Therefore, we do not offer quantity discounts.
For collections, large quantities of items, or specific projects, please contact us for a customized quote.
What kinds of items do you appraise?
We specialize in autographs and historical documents, including letters, manuscripts, dedications, photographs, books, signed artworks, shirts, balls, and other collectible items.
For other categories, such as antique books, jewelry, watches, luxury handbags, and vintage cars, we rely on partner specialists in Brazil and abroad.
What do I need to submit, and where?
Via WhatsApp or email, send clear photos of the item — front, back, sides, and important details — and provide the name of the signature's author, if known.
It is also important to share all available information about the provenance: where, when, for whom, and in what context the item was obtained.
What if I disagree with the conclusion?
The Preliminary Assessment represents the professional opinion of Mathias Meyer, based on the elements available at the time of analysis.
If you disagree with the conclusion, we recommend requesting a second opinion from another expert recognized by the market. The fee for the Preliminary Assessment is non-refundable.
How long does it take to receive the Preliminary Assessment?
The appraisal is sent within 24 hours after receiving the photos and necessary information for the analysis.
Is it possible to hire Glórias to facilitate the purchase of an item in an international auction?
Yes. Preliminary appraisal can identify the interest and potential value of an item, but Glórias can also offer, separately, an acquisition consultancy service. This service can include communication with the auction house, participation in or monitoring of bids, organization of payment and transport, as well as coordination of import to Brazil, including with a customs broker when necessary.
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