Plastic wrapping bands like this is used everywhre i guess, so collecting them should be easy.

They come in a couple of different sizes.I beleave this is the most common type.

The first thing I did was to paint the band in a grey color.

Then I rubbed it against something hard to remove the paint on top of the pattern.

The band was then cut in the right length and glued to 1mm cardboard.

The stairs look very good,and the band is very suitable for the 1:25 scale.