The inspiration for the chalk striped tropical suit worn around London recently (In the Pink) was this 1937 Esquire illustration.
Chalk stripes are not usually seen on summer suits these days, being generally confined to flannels. The thing about a chalk stripe is that in addition to its extra width compared to a pin stripe, the edges need to be a bit blurry, as anyone who ever saw a line on a chalk board will recognize. That blur is a byproduct of a flannel weave, but harder to pull off on a conventional worsted. The small irregularities of a high twist weave, on the other hand, lend themselves to a similar look.
That said, some may wonder at the idea of wearing a city suit on holiday. To which I reply that no less of an authority than the late Hardy Amies wrote about the disrespect that the tourist costume of shorts, tees and Birkenstocks shows to the inhabitants of the city one is visiting (OK, he never specifically mentioned Birkenstocks). And this does not even take into account the need to look appropriate next to such a well turned out companion.
The suit is dressed down slightly with the brown suede shoes, but the white shirt and dotted necktie would hardly draw a second glance at home or abroad.