| | Re: going to try koarkers...
I've successfully korked grosgrain, satin, the polyester with the loops like in the pic, velvet, glitter and organza ribbon.
Some types of ribbon I have to bake a little longer or use starch to get them stiff enough, but they all work well. You just have to experiment and play around to determine what works with your oven and the ribbon you are using.
I'm not sure what you mean by "ribbon with the metal markings".