WebDrawer (and the ServiceAPI) allow you to exclude Records (and other object types) from search results.  The trick is to find (or add) a routeDefault in hptrim.config.  In WebDrawer the record search already has defaults set in hptrim.config so you simply need to go to the routeDefaults elements, find the ADD element matching the one below and add the 'q' attribute. 

In the samples below the 'q' parameter will be added to every Record search.

In this example I only want to include electronic documents.

<add
  name="Record"
  model="Records"
  template="WDRecordList"
  q="electronic"
  properties="RecordRecordType,RecordExtension,RecordTitle,RecordNumber,RecordIsElectronic"
/>

In this sample I only want non-electronic documents.

<add
  name="Record"
  model="Records"
  template="WDRecordList"
  q="not electronic"
  properties="RecordRecordType,RecordExtension,RecordTitle,RecordNumber,RecordIsElectronic"
/>

NOTE: The 'model' in the routeDefault above indicates that the elelement applies to record search results.  A model of 'Locations' would apply to location search results.

More help: Route defaults are discussed in the online help shipped with the ServiceAPI under /help/routing.