Anything you do short of a custom paint job is going to be pretty fragile. With that in mind, why not just spray one side of the police tape with adhesive ad stick it directly to the frame? Quick and easy.

Any resin you find that is strong enough to maintain its shape/integrity only supported by thin plastic tape is probably going to be so thick and heavy that you'll hate it. I don't even know if something that would work for a bike frame is available - the stuff for bar tops is a pour-on-a-flat-surface deal.