Once you have created an Artstor user account, you can access the Digital Library without connecting to your institution's network by logging in to your account remotely. As a security measure, this remote access is set to expire after 120 days, but it can be re-set.
If you receive a message that your 120-day remote access period is expired you can re-set the 120-day countdown by logging in either on-site at your institution or through a proxy.
The 120-day remote access period is not available to registered users at public libraries, per the Artstor Digital Library's Terms & Conditions of Use.
Artstor remote access usually last 120-days, but for the duration of the COVID-19 crisis, Artstor is extending this feature to last 365-days. In addition, public libraries are eligible to register users for remote Artstor access.
If you have changed institutions, the remote access error message may indicate that you need to move your Artstor account to your new institution.