2 in the region of the edge 14 may be between 5 and about 30 of the first thickness sp 1 the edge 14 may be formed along at least part of the perimeter of the panel 1 or alternatively along the entire perimeter of the panel 1 the panel 1 may have a transition thickness sp 3 fig3 which is variable depending on the distance between the edge 14 and the central position p in particular the transition thickness sp 3 increases from the value of the second thickness sp 2 to the value of the first thickness sp 1 with a substantially logarithmic progression as the distance from the edge 14 increases the panel 1 has density values which vary from the central position p as far as the edge 14 moreover preferably the padding layer 20 in at least one portion of the panel for example the central area p has a variable density which is greater in the region of its external layer and smaller in the region of its inner layer advantageously according to the invention the structure created does not require any support frame in fact the edge 14 acts as a frame moreover the panel does not require any joint between sheet edges since no covering sheet is envisaged the covering in fact.