Actually, these academic papers on the left would work too. Rotate so they run vertical and you have a pinstripe.
The black paper in the centre here is like a modern pinstripe:
There's 2 pinstripes in this one:
And if you're thinking creatively, there are white pinstripes running through these beautiful plaid papers:
Lastly, the coloured striped paper just above the title banner, has thin white pinstripes between each colour.
Hope that helps.