A. Bringing a few materials files into SketchUp:
(1) Open SketchUp’s Materials inspector. ( Window > Materials )
(2) Click the “In Model” (house) button, or choose “In Model” from the dropdown list.
(3) Just drag any SKM file (from a File Browser window,) into SketchUp and drop on the thumbnail display area. (You need to do this one SKM file at a time. Currently SketchUp will not act upon multiple dropped files. Not even the first one, & ignoring the rest.)
B. Accessing any material files from within SketchUp:
If you put those files into some local collection folder like;
then you can add that as a local material collection.
IN the SketchUp Materials Inspector, click the little menu button (with the “Details” tooltip.)
Choose “Add collection to Favorites” and browse to your collection folder, then click OK button.
From then on you can access the collection from the dropdown list.
C. Starting every new model with all of your Material colllection inside :
(1) Choose a good template for you.
(2) Bring in SKM files as in A above.
(3) Save as a template with a generic name that indicates it is your setup.
(4) Set that template as the default. (Preferences dialog)
(5) Open a new model, model away,… save it as a unique model name.
(6) When done with the model, purge used materials and components. (ModelInfo > Statistics)
Note that using workflow C will cause slow load times for models, and waste memory until you do the purge.