Check the validity of the seals glued on the work and the certificate of authenticity. You must correctly press the polygons which are proposed to you by referring to those which are present on the certificate and the work . This control is 'blind' so as not to disclose the original ARTcertificate polygons. Attention, during a control step, you will not find any valid polygons, you will then have to press the 'Polygon absent' button. Be attentive!CLICK ON THE POLYGON OF THE WORK.