How you should open your paperbacks to avoid curved covers
Here is how you can protect your paperbacks these days when most books are glued. Be careful to avoid ending up with a curved / warped cover!
Do not open your book grabbing the outer sides!
You need to place your book on your desk or any table and open it from the inside, putting your fingers as near as possible to the spine. Push down the interior of the pages to open the book: do not grab the external edges. If you open your book the first time by pushing down, near the interior sides, next time it will open easily and you will be able to read without any fear of bending its cover!