Lid having a cured overprint varnish

A composite lid having an overprint varnish, which is used to cover a food-containing tray, wherein said composite lid is comprised of:

• a paperboard substrate having first and second sides;
• a coating of particulate minerals located exterior to said first side of said substrate;
• a layer of printed graphics located exterior to said coating of particulate minerals;
• a coating of a radiation-cured, heat resistant varnish located exterior to said layer of printed graphics, wherein said radiation-cured varnish is mass stable above 325.degree. F. and said varnish substantially prevents said layer of printed graphics from being distorted during a pressure platen heat sealing of said composite lid to a vessel and said varnish does not substantially adhere to said platen during said heat sealing wherein said pressure is at or around 60 psig;
• and
• a layer of a heat sealable barrier material located exterior to said second side of said substrate.