Tool textures (Source)

The tools textures can easily be found in Hammer by running "tools" as a filter word in the texture browser. These textures have extra attributes that most textures do not.

Note: Here's a tutorial on using many of the Source Tool textures shown below [1]

Image	Name	Special attributes
	Area portal	Use with func_areaportals and func_areaportalwindows
	Black
	Block LOS	Blocks the line-of-sight of NPCs and bots
	Block bullets
	Block light	Invisible; casts shadow like standard materials
	Clip
	Player clip control
	Fog
	Hint	Breaks up visleafs
	Invisible	Solid to all objects, invisible and does not cast shadows
	Ladder
	No Draw	Solid; Invisible; seals leaks; blocks visibility if used on all surfaces of the same brush
	NPC clip	Solid to NPCs but not players or other objects
	Occluder	Use with func_occluders
	Origin	Use to set the rotation origin of rotating entities; obsolete in Source
	Player clip	Solid to players but not NPCs or other objects
	Skip	Invisible; has no effect on anything
	Skybox	Use to make skyboxes
	SkyFog
	Trigger	Use on Trigger entities and Buyzones in CS:Source. First you create a brush with the block tool. Then select the trigger texture and apply to the brush (block). Set the block to entity or move it there. Now doubleclick the brush or block, then set it func_buyzone.