Do these curtains block out light?

No. They are semi-sheer, so they diffuse daylight and soften glare rather than darken the room. For a dark bedroom you would need a blackout liner or a different panel.

What rod size do the grommets fit?

Each panel has eight nickel grommets and fits curtain rods up to 1 1/4 inches in diameter. The header height is 4 inches and the bottom hem is 2 inches.

Are the panels sold as a pair?

Yes. Each set includes two panels, each 52 by 96 inches, for a combined width of 104 inches.

Machine wash cold with non-chlorine bleach only if needed, tumble dry low and warm iron as needed. The linen blend can wrinkle, so a quick iron restores a crisp look.

Is the color a true white?

No. The natural linen content gives the fabric a slightly brownish tone. If you want a solid, pure color, a different panel is a better match.

Will they help with energy use?

They add a layer at the window and reduce some light and heat transfer, but as semi-sheer panels the effect is modest compared with lined or thermal curtains.