Having recently made the swap fom plastic grocery bags to cloth, I have been seeing the insulated bags for frozen goods around. Despite their low cost, I decided to make one myself, hopefully a stronger one. I had some insulated wadding left over from a placemat/oven glove hit a few years ago so that is what started this, together with a few blocks left from a block swap.
I did the Chinese junk, but not the other one, I studied the cheap green enviro bags and made this one. It is twelve inches by twelve with an eight inch gusset. I already had the blue fabric and the grosgrain ribbon. Which is why some of it is black rather than blue. My main expense was the vinyl inner which I bought from eBay. I have a little left, but not enough to make another bag.
The zip was the hardest. My local small town store did not sell anything large enough so I thought I would use two smaller. Even then, I could not get two the same. It was very difficult getting the zip in at that angle, which I had never tried before. In the end, one of the corners ended up being handsewn as I gave up on the machine.
I have put all my enviro bags into it and it is in my car. I haven't tested it out yet, though, I hope it is sturdy enough.