No known copyright for Curt Teich postcards printed before 1964, with the following exception: if the Teich postcard has a photographer's copyright on it, or depicts a trademarked image, the user must seek permission from any holders of rights. For ease in dating Curt Teich postcards there is a dating guide available: link
Decade
InfoField
1950/1959
Place
InfoField
Italy--Venice
City
InfoField
Venice
Subject
InfoField
Rivers Ships Boats and boating
Subcategory
InfoField
River Scenes--Canals Ships & Boats--Excursion,Amusemen
Note that it may still be copyrighted in jurisdictions that do not apply the rule of the shorter term for US works (depending on the date of the author's death), such as Canada (70 years p.m.a.), Mainland China (50 years p.m.a., not Hong Kong or Macao), Germany (70 years p.m.a.), Mexico (100 years p.m.a.), Switzerland (70 years p.m.a.), and other countries with individual treaties.