This is a pannier bag clip I designed for making some DIY pannier-mount shopping bags for the rear rack of my bike. There are various other options about, but of course one always has their own vision, so I'm happy to contribute mine to future users. Now in version 2.

The shared files offer mirrored left and right options, which gives you a bit of adaptability to avoid support struts on your rack - place as you see fit. Swap sides if your spacing interferes with your rack structure.

They fit well with a positive snap for my rear rack made with 1.0cm steel tubing. That' might be different than what you have so measure your rack before printing. I used mine for a quick and simple shopping bag hack and that has worked well.

It seems to be beefy enough to hold some substantial weight. PLA isn't the strongest material, and with a bit of flex it can fail, but this seems to clip on nicely, with no scary cracking noises, and a slight inner lump to make it grip the tube.

It has a little hole tab at the top to accommodate an extra strap or bungee or something. In version 2 the strap hole has been rotated for easier access.

(Version 1 file remains shared in case you want a simpler structure for some reason. May remove later.)