Two paths can be chosen when selecting a mask. Sometimes these paths meet when the final decision is made and that is when an exceptional piece has been found.
One path takes you through the looks of the mask. Admire and compare it against other examples; consider if it appeals to you as it will be in your home or office for years to come. Check for the details that makes the mask unique or special, regarding materials and techniques.
The second path relates to connoisseurs: determine how old the mask is and of course, who the character represents and its role in the ceremony. The age can be estimated by the patina in the interior of the mask, but also by the different layers of paint on the front, cracks and restorations made to the piece.
Remember that these masks are rented to the dancers by Morerías (costume shops), so signs of use and age should be expected in an authentic Ceremonial Dance Mask.