These are obviously a much, much smarter solution to satisfying your blue mason jar needs than trying to dye them yourself... remember my failed attempt last year?
Jesse and I use mason jars for a lot around here. While I haven't tackled canning just yet (we do have a kit though and I am hoping to make my first attempt this summer, botulism be damned), we use mason jars for drinking water & smoothies, storing food, and displaying flowers. We are trying to cut out plastic as much as possible and I think some pretty blue jars will make this task even easier. Enjoy and stay homey!