Plastic Bag Keeper

I took Widewing's idea and modified it in three ways. I changed the size to fit how I fold the bags, I changed the side you grab from, and I made it a whole lot taller. I used his cap.stl and scaled it to match the size of my holder. (You need to scale it in your slicer.) It's included to save you the effort finding it, it's a nice design.

Folding instructions are supplied, Ikea style. The second to last fold is both outside to the middle, it allows the air to get out and let the bag fold flat. Done like this it comes out really close to 3" x 5". I made the holder a little oversized to allow for sloppy folding. Use Command Strips to sticks it to a wall or cabinet or leave in on the counter.