I created these because I was frustrated by the lack of options for framing finished cross stitch projects. A springy insert provides tension from the inside. They are not really suited for working on a project due to the bracing in the back which blocks access to the fabric.
There are 5 basic round styles in this collection, and one bonus hexagon shape.
I recommend printing the inner hoop with extra walls (3+) and possibly a gyroid infill for stability. It works well in PLA.
Depending on the tolerances of your printer and the thickness of your fabric you may need to adjust the X and Y scale of the inner hoop to get the tension you want. If it's too loose I suggest increasing it by 0.5 - 0.75 mm. Similarly, if it's too tight you can reduce the size a bit.
These are provided in 4 inch and 6 inch sizes. A STEP file is provided so you can create any size you like.