These mailers are not see-through in any way and are a beautiful black color. I measured the inner size, and it matches what the seller claims it is (10.5 x 15). The bubbles are on the smaller/thinner size. They are not the real thick and big cushiony ones. I sell a lot of cross-stitch kits, and this mailer size fits them perfectly. I have attached 2 pictures showing the size of a cross-stitch kit compared to the mailer. I also have attached a picture showing how a book looks with the mailer. These seem sturdy and could probably hold several items in them. The adhesive is sticky and did not tear apart when I tried tugging at it. This listing has a picture showing that you can write on these with a white marker. I tried doing this but unfortunately, if you barely rub or scratch against the words, it will easily erase due to the material it is. You don't want to write something on these mailers because the words could easily rub off when someone handles your package during the shipping process. I would use these mailers again for anything that isn't fragile and doesn't need extra cushioning. You could use these mailers for clothes, books, magazines, cross stitch kits (like I do), and more!