This is a clip designed to take two of your average takeout soup containers (116.5mm diameter, roughly a pint maybe?) and turn them into a humidity dome for rooting tree cuttings. One side of the print has an angled lip to prevent the need for supports (probably overkill) so just be sure to print this with the angled overhang on top. As long as you print as is in the STL, you'll be fine. I used PETG, as it is more durable and you do need to flex it a bit to get it to clip around the containers, but I assume PLA would work also.

UPDATE:
I added a second clip that adds a slot for a paper label. It should be printed with supports turned on "everywhere", but the overhang angle set to 75 degrees, so it doesn't print supports anywhere else on the print. I cut a piece of paper that is 16mm by 84mm then fold in half, label it and slip it in through the top.

HOW TO USE:
I've been using this dome clip for two weeks now. After receiving the fresh cuttings of apple, plum, nectarine, and apricot, I cut them to between 10-15cm, labeled them, wrapped them in wet newspaper, then stuck them in a ziplock bag in the fridge for two weeks. After that, I made a good potting soil mix with worm castings, coco coir, perlite and topsoil. I stuck the cuttings in the soil and watered thoroughly. Then I added the dome with the clip, stuck them in the window and let the magic happen. After another two weeks, every single cutting has started to sprout leaves and they look incredibly happy. I check on them once a day. I'm going to continue to leave them covered until I can see roots at the side of the container.