Here's a description and picture from paneristi about sandwich dials very interesting info for you. A much heard mistake is that early (pre-Vendome, pre-A) dials are called "sandwich dials". They are NOT. Prior to PAM 127 and the 1995 Historicals and some Radiomirs for sale now, only vintage Officine Panerai had real sandwich dials, where the luminous material was applied onto a separate disk under the actual dial and visible through cut-out numerals filled with varnish.
Here's a description and picture from paneristi about sandwich dials very interesting info for you. A much heard mistake is that early (pre-Vendome, pre-A) dials are called "sandwich dials". They are NOT. Prior to PAM 127 and the 1995 Historicals and some Radiomirs for sale now, only vintage Officine Panerai had real sandwich dials, where the luminous material was applied onto a separate disk under the actual dial and visible through cut-out numerals filled with varnish.