They don't really provide a lot of protection from the sunlight that comes pouring in around 2 in the afternoon. Maybe not the best choice, but they were about $4 on clearance at Lowes and we needed shades, so home they came. Well we've lived with the glare on the TV and the squinting while trying to read long enough.
What to do? Buy new shades? Well that's not really in the budget. Well why line the back with something? So the hubs and I tried some upholstery fabric, home decor fabric, muslin and finally felt. We settled on felt the same color as the shades. It let in some light, but diffused the light coming in enough that we no longer felt like we were living on the sun.
Here's what we did.
We took the blind down and stretched it across the dining room table. Next I measured the blind, I kept the felt in about 1" from either side. You could go all the way to the edge, we had stitching running down the shade at 1" in so I felt it was a convenient place to hide my glue seam (though after doing this the glue didn't seep through at all, so this wasn't really an issue). If you're blind is a full length (I think our windows are 63" tall) I recommend using a rottery cutter to cut your fabric.
When I got to the end I ran glue across the bottom and secured the felt to it.
Wow...look at that! You lined a shade.
I paid about $4 for the felt bringing my investment for the shade to a whooping $8.
The motto in our house is "It's broken, fix it!".