Bertmar was the name that the Canadian jewellery firm People's Credit Jewellers (now People's Jewellers, operated by the Zale Corposation) applied to their private label watch lines. Frank Gerstein, the founder, had two sons in the business by the names of Bertrand and a Marvin. Hence BERTrand MARvin was the name given to the watch lines. Just thought you might like to know.😀