Excluding material or adding material to the Modeled Only Collection are both ways to hide material that isn't going to be estimated, sold or shipped. However, there is one major difference to be considered, Modeled Only Collection will be placed in a layer which a designer can turn on/off.
Add to Modeled Only Collection
Adding material to the Modeled Only Collection is quick and easy - Either pre-select multiple members or a single member, right-click and select Add to Modeled Only Collection.
Material that has been added to the Modeled Only Collection will be placed in a layer which a designer can turn on/off.
Material that has been added to the Modeled Only Collection, similar to Excluded Material will be hidden from the materials list:
Exclude Materials
To simply exclude material from the materials list, navigate to the Drawing and Markup Ribbon (tab) and select Exclude Material from the Material List section.
There will be a prompt in the lower left to Select materials to exclude from the Layout Materials List (right click to accept).
Materials selected for exclusion will be highlighted in green until accepted with a right click.
Clear All Excluded Flags
To show hidden material again, right-click on the Layout Materials List and under Material List, select Clear All Exclude Flags.