Interlibrary Loan requests are appropriate when the sources you need are not available in full text through library subscriptions.
ILL requests take time for our staff to process and fill. Work ahead when you know you will need to use it. If you are working on a tight deadline, try using the "Full Text" filter in OneSearch to avoid search results that require ILL.
Click Journal Finder links in OneSearch or search directly in Journal Finder to make sure what you're trying to get is not already accessible, before you submit an ILL request.