You can check out the plans for these ledges here. The lumber only cost about $9 for one. I made mine six feet instead of eight feet because the size suited my needs better. I already had a ton of frames on hand (I tend to collect them) and I had the paint as well. I like the red, black, and white together, although you can't tell some of them are red in this lighting. The other night I uploaded about 50 pictures to put inside them, all in black and white (still need tp pick them up). I think this collection is going to look great.
I painted them with Behr paint that I already had on hand. The color is "off white". After they had two coats of paint, I sanded them again to distress the edges all around. Then I glazed them with Ralph Lauren's faux glaze in "manchester brown" to give them a rustic look. I love how the wood looks really old. Just what I was going for!
A word of caution- when you go to purchase your 1x4s, make absolutely sure that your wood is not bent or warped. I was careless about it and I bought a couple pieces that should have been more straight. If you look closely, you can see that one ledge is slightly warped on one side. But it just adds to the antiquish look...right?? RIGHT??
Also, the plans say to use 2" finishing nails in the front. That is way too long and only makes it more likely that they will split the wood. Since you are only nailing them into a very thin piece which is less than 1" in thickness, chances are you will nail it in slightly off center and 2" nails almost ensures it will not be a good thing. So go with thin nails at about 1" in length.
Have fun building!