Starting with variable specs, where the spec type equals File. The choices are image, printable PDF and "other." The maximum size fields defaults to 80 KB, but you can enter a value in this field up to and including 10,000 KB (i.e. 10 MB). 

For static specs, where the spec type equals File, the maximum file size is 10MB. If you need to provide access to larger files, consider creating a text spec and entering the URL that points to the file.

Turning now to the large and thumbnail images, in Storefront 2.0 there is no size restriction. But you should consider the user experience and how it could be affected by having to load large images.

There is no size limit on files uploaded to the themes folder. For files uploaded in a project folder, we recommend 10MB or less. You are able to upload larger files, but they may cause rendering issues, especially during peak system usage.