ThingWorx Model Definition and Composer > Visualization > Masters
  
Masters
A master provides consistent framing of a mashup’s contents (similar to the concept of a master page or template), and is commonly used for items that display throughout the mashup, such as logos, menus, and titles. For example, to display a company logo throughout your mashup, a master can be created to display the logo, so that no matter where the user is in the mashup, they will see the company logo in the same place. Masters are also commonly used for menus. In order to provide the same navigation options throughout a mashup, a menu is located in the same place throughout the mashup and contains the same options.
You can associate a master with a mashup by assigning the Master Property in the mashup properties. You can create different Masters for different mashups, or one for all of your mashups.
Within a mashup, if you have a refresh service running, the master does not refresh.
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Always assign the Master to any mashup so that a user is able to open it directly (for example, by accessing via https://<server>/Thingworx/Mashups/NameOfMashup).