A compendium of resources in the public domain.
Der Ornamentenschatz; ein Musterbuch stilvoller Ornamente aus allen Kunstepochen or (The ornamental treasure; a sample book of stylish ornaments from all periods of art) I chose this book to share because of the beautiful ornaments and Chromolithographs. Below are just 2 examples of the images you will enjoy in this book. Thanks to Archive.org Dolmetsch,
Source: Collection of architectonic exterior and interior ornaments for budding master builders and lovers of architecture: Riedel, HC (Henry Carl), 1756-1820: Free Download, Borrow, and Streaming: Internet Archive
(Alcune decorazioni di nobili sale ed altri ornamenti) Some decorations of noble rooms and other ornaments: Albertolli, Giocondo, 1742-1839 Source: Some decorations of noble rooms and other ornaments: Albertolli, Giocondo, 1742-1839: Free Download, Borrow, and Streaming: Internet Archive