Here is a bag clip for your potato chips! Print the male and the female side. Only 1 spring insert is needed. You choose the desired thickness of the spring based on the strength you need with the type of filament you're using. Also, depending on your nozzle diameter and slicer program, you may find that the thicker spring may be more flexible. That's why I included 3 options.

The one in the picture is entirely made from PLA using the THIN spring insert. With my Slic3r program, the THIN insert was a tad stiffer than the REGULAR due to the way the perimeters were made. And the THICK insert was way too stiff for me. But it may come in handy when using ABS since it's more flexible.

All parts printed with PLA using a .5mm nozzle and .38mm layer height using Slic3r.

Support material is built in to the male and female sides. No need to generate any of your own support material.

I would recommend using a nozzle .4mm or smaller for best results due to how thin some of the parts on the male hinge.