Look Files for Palettes of Materials
As well as being used to contain the Materials used by a specific asset, Look Files can also be used to contain general collections of shaders. This is particularly useful if you want to have studio- or show-standard sets of shaders created in 'shader development', which are then made available to other users. Another use of shaders from Look Files is to pre-define standard shader sets for lights (including light shaders made out of network shaders) to be brought in for Lighting.
Materials can be written out into a Look File using the LookFileMaterialsOut node. LookFileBake also has an option to 'alwaysIncludeSelectedMaterialTrees' that allows the user to specify additional locations of materials they want to write out into the Look File whether or not they are assigned to geometry.
To bring the materials from a Look Files into a project you can use the LookFileMaterialsIn node.