If you are a Print Studio and you are using an Upload Store you can allow customers to upload multiple images at once. The Upload Store does not do this by default so you will have to enable this manually.
Log in to your Art Storefronts Control Panel and click on the Art Upload Store you want to work on. We will be using the store named Upload Store.
Click on the tab labeled Info.
Scroll down until you see the section labeled Type of Buying Experience. In the drop-down menu select Multiple Images At Once.
Once you are satisfied with your changes, click Save.