(The following information and screenshots relate to the latest version of the Papers app. For instructions on the classic version, please click here.)
When you select a reference in your library, the side panel on the right side opens. At the top of this panel you'll see a number of options for your article, including the "Files" option. Selecting this option will allow you to see all files associated with that reference.
To add new files to that reference simply drag-and-drop them to the empty space in the panel or click on the "+Add files" button at the bottom:
To delete a file click on "More" next to the file you want to delete and select the "Delete File" option:
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Papers Classic
(the following instructions are for the classic version of Papers)
When you select a reference in your library, the right-hand side details panel opens. At the top of this panel, you'll see other options for your article including "files". Note: if a supplement is already present, the number of additional files will appear in red.
Select the "files" icon to view the files associated with an article.
In order to add a new supplement to the article, while the "files" tab is selected drag and drop any additional PDFs directly into the blank space available or "+Add Files" at the bottom of the panel:
To delete a file from a reference, click on "More" and select the "Delete File" option:
