This is pretty good stuff right here. See, there is carpets printed on paper, but paper isn´t flexible enough to snug on stairs or other profiles. That´s why we have soft bare metal foil included in this set. The foil might be sanded up a lil bit, then primed with Mr. Metal primer (or with enamel clear varnish) and a normal primer.
Hit that with White or Egg Shell and and you have your carrier medium (foil) prepared for the decal. Apply the decal (including using a setter)  and seal it with Clear varnish. Allow it to dry. Now you might give it a coat of Matte varnish, eleminating any gloss. Consider using a slight filter of oil paint in order to change the hue and eliminate any reflective spots if neccessary.
Enjoy