Kraft envelopes are NOT recyclable!
If you look at the picture above, you will notice 3 different types of envelopes. The one on the left is recyclable with cardboard paper. The one in the middle is recyclable with office paper. The one on the right, "Kraft" paper, is NOT recyclable.
Why, you ask, is it not recyclable? Well, because of the dye techniques. Unlike the first 2 envelopes, the goldenrod envelope is dyed with a heavy-metal that is pounded into the fibers itself. The industry term is "beater dye". Because the dye is inside the fiber instead of just printed on top, the fibers cannot be recycled.
One way to tell the paper is dyed with the beater dye is to tear the paper. If the fibers in the tear are white then the paper is most likely recyclable. If the fibers in the tear, you know, kind of underneath the top layer, are NOT white, then the paper is most likely NOT recyclable.
Why are some envelopes and some colored paper made this way? Some manufacturers use this process to hide color or specs that one can sometimes see in plain paper, especially recycled paper.
So the biggest thing to be concerned about is that you may be purchasing products that are "recycled" but are not "recyclable".
What to do instead? Only use paper and envelopes that are recyclable with either cardboard or office paper. You dig?