Blackout

Area 
Shrouds the affected area in impenetrable blackness. No one can see into the affected area, and no one within the affected area can see anything; see p. B394 for combat rules. 
The Dark Vision (P, X) advantage lets you see through a Blackout spell, but Night Vision (P) and Infravision (P, X) do not.

Duration: 1 minute. 
Base cost: 2 to cast. 1 to maintain. 
Prerequisite: Darkness.

Item 
Floor, ground, or a rug can be enchanted so that the area above (about 6 feet) is in permanent blackout. 
Energy cost to create: 15 per square foot.