Thank you for your message. A cord will typically be a bit stronger than that of flat elastics, yes. 
As to the application, we can't say whether this would be suitable as typically cords can be harder to work with than that of flat elastics.
If unsure to it's suitability we would recommend opting for a small sample which can be ordered from our sample page. To order just add the product code or name into the text box provided before adding to your basket. We provide up to 8 samples of any of our cut length ribbons, bias & tapes as such if you require any other samples these can be added into the text box before adding to your basket.

I hope you find this information helpful.

Kind Regards
Mark