The new Libraries panel in Photoshop CC (Window > Library) is a powerful way to store different design elements in an easily accessible panel, which can then be quickly applied across multiple documents as well as shared with Adobe Illustrator.
For example, if you have a logo that you regularly add to documents, you can open your logo file in Photoshop, select the logo layer in the Layer’s panel (or Layer Group if the logo is made up of multiple layers) and click the Add Graphic icons at the bottom left of the Libraries panel to “store” the logo in the panel. This “stored” version is saved locally as well as copied to the Creative Cloud making it accessible across multiple installs using the same Adobe ID. (For example, if you have two copies of Photoshop installed – one at home and one at work you will have access to the content of your Libraries panel in both locations).
When you want to apply that logo to additional documents, drag and drop the logo icon in the Libraries panel on to the open document. Note: you can also drag from the document area into the Libraries panel to store a Layer/Layer Group and, if you prefer, you can right mouse click on the icon in the Libraries panel to select “Use in Document” to apply that layer to another document. You can also Control -click (Mac) | Right -click Win to see additional options for each of the elements stored in your Libraries.
In addition to storing graphics (including Layers, Layer Groups, and Smart Objects), text styles (including font, type style, color, size, tracking, and leading), layer styles, and colors (fill, stroke, and foreground) can all be added to the Libraries panel. The Libraries panel can display brushes that are captured via the Adobe Brushes app (but not brushes created in Photoshop). If you have saved items in the Libraries panel in Adobe Illustrator, you will see those items in your Libraries panel in Photoshop and vice versa. If the element is understood by both products, then you can use them across applications. If the item being stored is specific to one application then, although you can view it in the Library, you will not be able to use it. (There might be some debate over whether or not we should be able to see items in a Library that we can’t use, but I believe it’s better that we can see all of the items regardless if we can use them or not – which could potentially cause confusion and lead us to believe that they are “missing” from one Library or another).
You can create as many Libraries as needed to help organize commonly used assets for different projects (click on My Library and choose Create New Library from the drop down menu).
You can view these assets in Creative Cloud by choosing View on Web from the fly-out menu on the Libraries panel.
If you are not online, you are still able to use items stored in your Libraries (a local, offline, copy is available). Any changes will be synced once you get back online. Note: the content stored in Libraries is not “linked”, meaning that if you add or apply the item that is saved in the Library and then make a change to that content in the document, the layer style, graphic, color etc., will not be automatically updated in the Library.
In addition, although technically the Libraries panel can support any size graphics (including Layer Groups that might include multiple, high resolution smart objects), I wouldn’t recommend storing really large files in your Libraries as they might reduce performance. There is a limit of 1000 elements in the Libraries.
Finally, setting type in a layer in Photoshop CC and then saving it as a Type Style in the Libraries panel enables that Type Style to be used in Illustrator. It would be useful to have Libraries use Paragraph and Character styles from Photoshop, but unfortunately there are slight differences between the way that the type engines in Photoshop and Illustrator display some type attributes.