Recommendation of different materials for 3D printing flexible parts

I am planning to 3D print this part from solidworks.

I am hoping to achieve a good level of flexibility with the clasps in this part.

• Thin circular arc in the Top drawing.

and

• Wider circular arc in the Front drawing.

The only flexible materials I have access to currently in the lab I work are nylon and polypropylene. I’m not sure which is a better, so I would like to get some recommendations. The flexibility I am looking to achieve is similar to that of the handle on a pen cap. I want the clasps to be able to flex enough to snap onto a circular tee without breaking, and if necessary be pulled open to take the part off again.

The thickness I am thinking of printing at is 0.1 mm thickness but I also need to be able to have the labels and tick marks be clear enough.

Ultimately I’m only interested in which material is best. Thanks.