Berthil is a male model that has appeared in ad campaigns for Saks Fifth Avenue and has also been in editorials.
Berthil is signed with LA Models Los Angeles, Kult Model Agency Hamburg, Sight Management studio Barcelona, Select Model Management London and New Madison Paris.
In 1998 he was in the spring ad campaign for Nine West.
In 2009 he was in the fall ad campaign for Banana Republic with his wife and model Lorie Baker that was photographed by Richard Phibbs.
In 2010 he was in the fall ad campaign for Saks Fifth avenue. He was in an editorial for the September issue of V Man that was called Heartbreakers, which was photographed by Richard Burbridge.
In 2013 he was photographed for Lands End.
In 2015 he appeared in an editorial for the January issue of Esquire Mexico that was called Boldness in NYC that was photographed by Matthew Scrivens. He appeared in an editorial for the April issuer of Esquire that was called Scenes from a Marriage, which was photographed by Marcelo Krasilcic. He was in an ad campaign for Brooks Brothers. He was also in the look book for Boggi.