In the app, “collection” and “catalog” refer to the same thing: a named space with a description that will hold your artwork records.
You need a user account. Registration is free; from the private area you can create artists, catalogs, and artworks with no install required.
The interface uses straightforward forms. You do not need technical skills to fill in title, description, images, and details for each piece.
Wireframe: site header and access to sign up or log in.